Croque Monsieur with French Onion Relish

  Croque Monsieur with French Onion Relish

I am so glad that this week is finally drawing to a close… as it was the dreaded mid-exam period. With all the finishing touches that had to be added to assignments, I barely had time to relax and put my feet up! That’s why I am so glad this week is coming to an end as it signifies the end of assessment… which is always a cause for celebration!

Every so often I get a craving for anything containing gooey, melted cheese. It’s definitely not the healthiest of cravings, but sometimes cheesy comfort food can be justified. For me, an all-time favourite celebratory food is a decadent Croque Monsieur.

Croque Monsieur with French Onion RelishCroque Monsieur with French Onion Relish

This Croque Monsieur is a modern reinvention of the Parisian classic… it is super indulgent and definitely not for the faint hearted. Smoked prosciutto is wrapped around crispy slices of sourdough bread which is filled with an oozing mixture of gruyere, sage, dijon, crème fraiche and a caramelized french onion relish. The sandwich is then fried in butter to develop that all important crunch. The butter further imbues the sourdough and prosciutto with a rich nutty taste.

Croque Monsieur with French Onion RelishCroque Monsieur with French Onion Relish

If you’re going to cook a Croque Monsieur, you may as well cook it right… don’t skimp on full fat and good quality ingredients! Make sure you use a good quality cheese. For me, gruyere is the best out of all european cheeses… the splurge on a block is always warranted, especially if it’s for a celebratory occasion. Its strong and rich taste really makes all the difference and is perfect to balance out the sweetness of the french onion relish and saltiness of the prosciutto.

Croque Monsieur with French Onion RelishCroque Monsieur with French Onion Relish

Eat your Croque Monsieur hot of the pan, to best appreciate its oozing, molten and rich centre. This Croque Monsieur is definitely the king of all sandwiches, perfect for any day of the week or special celebration!  

Croque Monsieur with French Onion Relish
Serves 4
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For the Croque Monsieur
  1. 125g of gruyere cheese, grated
  2. 2 tablespoons of Dijon mustard
  3. 120g of creme fraiche
  4. sea salt and cracked black pepper
  5. 8 slices of sourdough bread
  6. 12 sage leaves
  7. 12 slices of prosciutto
  8. butter for frying and to lightly coat the bread
  9. kitchen string
For the French Onion Relish
  1. 1/3 cup of olive oil
  2. 10 large french shallots
  3. 1 teaspoon of garlic
  4. 2 tablespoons of white wine
  5. 2 tablespoons of brown sugar
  6. 1 tablespoon of thick balsamic vinegar glaze (i used truffled infused balsamic vinegar)
  7. 1 teaspoon of salt (i used truffled infused salt)
For the French Onion Relish
  1. Add half the oil to a pan over low heat, once hot, add the onions and sweat until they loosen.
  2. Add garlic and white wine. Let reduce until onions have absorbed most of the liquid.
  3. Add the brown sugar and stir to coat the onions, once the onions and sugar have absorbed all the remaining liquid. Add remaining oil and balsamic vinegar glaze. Add salt and stir.
  4. Let onions simmer in mixture over low heat for ten minutes or until sticky and caramelized. Remove from heat and set aside.
For the Croque Monsieur
  1. Mix the gruyere, dijon, creme fraiche in a bowl. Add a sprinkle of salt and pepper.
  2. Lightly butter the slices of sourdough bread, then spread one slice of the bread with the mixture and top with onion relish. Sandwich with another slice of bread.
  3. Cut each sandwich into 3 pieces (or instead of creating sandwich fingers, the sandwich can be left whole).
  4. Place a sage leaf ontop each finger and then wrap a slice of prosciutto around each sandwich finger. Then with kitchen string secure the prosciutto and sage leaf in place (This can be kept on for presentation or removed later).
  5. Heat a non-stick pan with butter over medium to high heat. Once the butter begins to bubble cook the sandwiches on each side for 3 to 5 minutes or until golden, crispy and the cheese has melted.
  6. Serve hot!
butter and brioche
 Croque Monsieur with French Onion Relish


  • Reply May Your Days Be Merry and Bright – A Moveable Fete January 20, 2016 at 3:18 pm

    […] Croque Monsieur with French Onion Relish: these were a huge hit but oh-so-messy and had to be continuously fried throughout the day.  Again, also not a traditional croque monsieur, which is one of my favorite sandwiches alongside its kin the croque madame, but still hit the spot.  Unfortunately/fortunately, they were really popular, especially with my male guests, so I kept having to run back to the kitchen…to make a sandwich (ugh, the joke just writes itself). […]

  • Reply Lori - The Kitchen Whisperer March 23, 2015 at 2:51 am

    So I’ve been literally drooling over your site for the past 20 minutes and this, THIS stopped me dead in my tracks to the point I looked at the clock and thought “Hmmm, 10:50pm isn’t too late to go to the store to get the ingredients to make this, right???” LOL

    Thalia my friend… AMAZING!

    Best Kitchen Wishes!

  • Reply Jen L | Tartine and apron strings December 28, 2014 at 4:10 am

    Oh. Definitely the prettiest Croque Monsieur I’ve seen! Drooling…

  • Reply Christine December 3, 2014 at 3:07 pm

    These look so gorgeous!! I adore Gruyere cheese but then adding prosciutto to the mix? Yum! I have to make these soon! Pinned!

  • Reply the beer and food project November 12, 2014 at 2:53 am

    These look amazing! We’ll be trying them soon over at the BAFP’s kitchen! I have a special Belgian Pale Ale whose hops, I suspect, will cut the Gruyere just enough and whose yeast will complement the salt in the proscuitto and the slight funk of the cheese. Cheers!

  • Reply Bec October 24, 2014 at 12:14 pm


    that is all.

  • Reply Kayla October 1, 2014 at 7:30 pm

    My goodness, these look incredible. Your recipes all seem so beautiful, I can’t wait to try some out! I’m currently living in France for a few months (I’m from Canada, and am enjoying french food too much…Can’t wait to make these for my three male roommates…they will be very happy boys!!

    • Reply thalia October 1, 2014 at 11:58 pm

      very jealous that you are living in France Kayla.. enjoy! x

  • Reply Dedy@Dentist Chef September 10, 2014 at 5:54 pm

    lipsmacking delicious crispy savoury croque monsieur parcell, good job!!!

  • Reply Kari Peters September 10, 2014 at 4:04 pm

    These sandwiches leave me utterly lost for words! I keep envisioning the creamy creme fraiche mingling with the cheese and it’s making me crazy!

  • Reply Amanda - A Cookie Named Desire September 9, 2014 at 8:09 pm

    I love Croque Monsieur…. one of my favorite memories from living in London was this little cafe in the train station that sold different variations on this sandwich and I would always get one just before hopping the train to my next destination. Pinned.

  • Reply PASSTHEKNIFE September 8, 2014 at 2:55 am

    You always have the most comforting dishes. This looks incredibly delicious but also so lovely. These would perfect passed at a party.

  • Reply Daniela @ FoodrecipesHQ September 7, 2014 at 4:16 pm

    A very original and beautifully prepared recipe. Love your version of croque monsieur, it looks like something precious, almost like a gift you don’t want to unwrap!

  • Reply kristie @ September 7, 2014 at 3:22 am

    Wow, these look unbelievably delicious! I have never had French onion relish. But now I want to make it and put it on everything.

  • Reply Patricia @ Grab a Plate September 6, 2014 at 11:31 pm

    Oh wow! These look amazing & just love your presentation!

  • Reply Suzanne @ Flour Arrangements September 6, 2014 at 11:06 pm

    I don’t often think sandwiches are beautiful, but these, with the prosciutto wrap over sage leaf, are simply stunning.

  • Reply Andrew Bui September 4, 2014 at 8:37 pm

    Looks beautiful!

  • Reply Russell from Chasing Delicious September 4, 2014 at 6:46 pm

    What a beautiful presentation! Such a fabulous recipe too.

  • Reply Marissa | Pinch and Swirl September 4, 2014 at 6:18 pm

    This is one of my all time favorite breakfasts, but you’ve made it more beautiful than anything I’ve ever had the pleasure to eat. And wrapping it in prosciutto is genius!

  • Reply Jessica | A Happy Food Dance September 4, 2014 at 12:18 am

    Thalia – this looks incredible. I have never seen a croque monsieur done this way but I love prosciutto so much you could wrap it around rocks and I’d eat it. Pinned!

  • Reply Stacey | Kitchen Serendipity September 3, 2014 at 10:19 pm

    YUM!!! That sounds delicious!!!

  • Reply Kyrstie @ A Fresh Legacy September 2, 2014 at 10:11 pm

    Oh my goodness, these look amazing!

  • Reply Kelly - Life Made Sweeter September 2, 2014 at 10:48 am

    These little croque monsieurs look amazing!! I love the crispy layer and french onion relish – so delicious!

  • Reply Johlene September 2, 2014 at 8:48 am

    Oh wow these are simply beautiful, they look SO good! Thanks for your comment on my blog too! xoxo

  • Reply Christine September 2, 2014 at 4:37 am

    Oh. My. Gorgeous! This looks like an ultra-hip,very classy way to do such a comforting homestyle dish. I love it! (Squeals in office.)

  • Reply Tieghan September 2, 2014 at 4:31 am

    Wow, this looks incredible! So pretty!

    • Reply thalia September 2, 2014 at 6:05 am

      Thanks Tieghan! x

  • Reply Michelle @ Flour and Aprons September 2, 2014 at 3:05 am

    They look amazing! I haven’t had lunch yet and I could really go for one of those right now. 🙂

  • Reply Alyssa @ My Sequined Life September 2, 2014 at 2:24 am

    Oh my goodness Thalia – this looks incredible! I hear you on celebrating things with food. Specifically gooey, high quality cheese like gruyere. And prosciutto. YUM!!

  • Reply Rachel @ Bakerita September 1, 2014 at 10:48 pm

    Eating this seems like it would be a magical experience. NEED to try this!!

  • Reply Katie September 1, 2014 at 9:57 pm

    Thalia these look so tasty! I could eat about 5 right now.

  • Reply Louisa [Living Lou] September 1, 2014 at 11:32 am

    Wow talk about a delicious sandwich! This looks perfect for cooler days in fall. Also, I’m with you on your feelings about exam period, there’s no better feeling than getting through those stressful days.

  • Reply Danielle | Krafted Koch September 1, 2014 at 1:56 am

    Oh my goodness! Fried sage, cheese, onion, bread…does it get any better than this?! FANTASTIC!

  • Reply Blue Cheese Burgers - erin made this August 31, 2014 at 11:37 pm

    […] Onion Jam adapted from Butter and Brioche Brioche Buns adapted from Portuguese Girl Cooks […]

  • Reply Angie @ FridayCakeNight August 31, 2014 at 4:21 pm

    As I’m sitting here in my pj’s, I really want one of those! The sage leaves look beautiful tucked in there!

  • Reply Courtney @ Pizzazzerie August 31, 2014 at 2:59 pm

    These look SO good! Definitely adding to my must-try-STAT list!

  • Reply Joanne August 31, 2014 at 2:53 pm

    Cravings for melty cheese are par for the course around here! And by that I mean – a daily occurrence. Chowing down on one (or five) of these sounds ideal for satisfying them.

  • Reply judy @ I'm Bored, Let's Go August 31, 2014 at 1:43 pm

    Most appetizing Croque Monsieur I’ve ever seen!!!

  • Reply Chris @ Shared Appetite August 31, 2014 at 1:11 pm

    Thalia, I’m drooling over these gorgeous sandwiches! They are perfect! Pinning 🙂

  • Reply Sonja August 31, 2014 at 1:02 pm

    These are so adorable… I think I just got a winning idea for the next brunch I’m hosting 😉

  • Reply Ashley August 31, 2014 at 2:16 am

    Whoa these look amazing! That french onion relish! Man, you are making me hungry right now! haha

  • Reply DArina August 30, 2014 at 9:59 pm

    These are so cute. I love, love croque monsieur. Thanks for sharing!

  • Reply Kate @ ¡Hola! Jalapeño August 30, 2014 at 2:57 pm

    These sandwiches are drop dead gorgeous! Wrapping them in proscuitto is pure genius.

  • Reply Leah | So, How's It Taste? August 30, 2014 at 12:18 pm

    These look amazing! I’m such a sucker for a croque monsieur and I love your twist on it. Great presentation!

  • Reply Lisa @ Healthy Nibbles & Bits August 30, 2014 at 6:45 am

    I love the presentation of these! I just want a bite right now!

  • Reply Tina @ just putzing around the kitchen August 30, 2014 at 4:26 am

    OMG this looks insanely delicious!!! Definitely gonna save this recipe for later

  • Reply Haley @ Cheap Recipe Blog August 29, 2014 at 9:37 pm

    These are absolutely adorable!!

  • Reply Olivia - Primavera Kitchen August 29, 2014 at 7:19 pm

    Looks absolutely gorgeous and flavourful!

  • Reply shelley @ Bacon Egg & Cheese{cake} August 29, 2014 at 6:06 pm

    Oooh these are beautiful 🙂 The string is so cute and the sandwich sounds amazing!

  • Reply Giulia August 29, 2014 at 6:02 pm

    wow, these look amazing. These would be perfect as appetizers at a cocktail party! Yummy!

  • Reply Immaculate August 29, 2014 at 4:18 pm

    These are my kind of croque monsieur taken up a notch with onion relish-YUM!

  • Reply Sarah August 29, 2014 at 4:04 pm

    These photos are practically edible… wow! And I happen to have some creme fraiche to use up. Enjoy some time off from school!

  • Reply Mandi August 29, 2014 at 3:54 pm

    Cor, this is right up my street! And beautiful, too! Nice work 🙂

  • Reply Maggie August 29, 2014 at 3:03 pm

    My first favorite breakfast dish. My second favorite is croque madame 🙂
    Your photo looks amazing! Seriously! The cooking is a bit intimidating for me, but I will save the recipe to cook with my boyfriend 🙂

  • Reply lisaiscooking August 29, 2014 at 2:22 pm

    What a great reinvention of the croque monsieur! They look like a delightful mix of crispy and gooey–and they’re so cute.

  • Reply Kristi @ Inspiration Kitchen August 29, 2014 at 2:12 pm

    Oh my gosh – before even trying these, I can already tell they are my new favorite dish. I love every single one of those ingredients – gruyere, sage, prosciutto in a crispy, buttery shell? Yes, please! Pinned!

  • Reply Linda @ Fit Fed and Happy August 29, 2014 at 1:04 pm

    New Reader here!

    Your photography is impeccable–do you only post recipes, though?

  • Reply Meinhilde August 29, 2014 at 11:23 am

    These look absolutely amazing – I’m sure they tasted how they looked!

  • Reply Helen @ Fuss Free Flavours August 29, 2014 at 10:10 am

    This is stunning! a croque monsieur made elegant!

  • Reply Gourmet Getaways August 29, 2014 at 5:10 am

    Wow! I’m in heaven, LOL. If ever I’m gonna faint, it’s because of the goodness in every bite. Thumbs up!!!

    Gourmet Getaways

  • Reply Mira August 29, 2014 at 3:55 am

    They look so fancy and beautiful! I’ll try them soon!

  • Reply Paula @ Paula's Plate August 29, 2014 at 1:52 am

    So glad you made it through your crazy week! I am loving this updated twist on a delicious classic, it looks wonderful 🙂

  • Reply Christin@SpicySouthernKitchen August 29, 2014 at 1:49 am

    I am dreaming that I am biting into one of these right now! They could not look more delicious! The onion relish sounds fabulous.

  • Reply Anna @ Garnish with Lemon August 29, 2014 at 12:09 am

    Oh. My. Word. I’m a huge fan of anything French Onion, and this completely tops anything I’ve seen. Beautiful!

  • Reply Medha @ Whisk & Shout August 28, 2014 at 11:17 pm

    Stunning pictures and the french onion relish is a creative and classy twist 🙂

  • Reply Ashley | Spoonful of Flavor August 28, 2014 at 9:37 pm

    I love everything about these! I love mini versions of food and these croque monsieur’s are perfect!

  • Reply Maryanne @ the little epicurean August 28, 2014 at 9:37 pm

    Who craves healthy foods?! These croque monsieur look absolutely delicious! I hope you have a relaxing weekend 🙂

  • Reply cheri August 28, 2014 at 8:44 pm

    Love your twist on this classic recipe, it’s so well thought out, love each component! well done!

  • Reply ATasteOfMadness August 28, 2014 at 7:30 pm

    Wow. This looks so fancy! I would sure love to try this

  • Reply Dannii @ Hungry Healthy Happy August 28, 2014 at 7:04 pm

    These look amazing! So creative.

  • Reply Karen-2Teaspoons August 28, 2014 at 6:33 pm

    These look delicious and adorable! I love the little sage leaf and twine! I wish I could bit into one of these right now…I’ve always had more of a gooey-cheese tooth than a sweet tooth 🙂 Also, congratulations on getting through mid-exam week!

  • Reply Gerlinde August 28, 2014 at 6:21 pm

    Croque Monsieur is great comfort food and I love it .Your presentation is wonderful and adding prosciutto , sage and the onion relish genius. Thanks for sharing.

  • Reply Crystal | Apples & Sparkle August 28, 2014 at 4:37 pm

    Such a gorgeous presentation! And so delicious too!

  • Reply Lindsey @ Piecemaker August 28, 2014 at 4:33 pm

    Wow, these look absolutely divine! Love how you completely dressed up a classic while still keeping it simple. This is my first time on your site and I’m so glad I visited 🙂

  • Reply Farah @ The Cooking Jar August 28, 2014 at 4:06 pm

    Can I just say how great looking that is? What a great way to enjoy cheese and have some crunch too!

  • Reply Stacey @ Bake.Eat.Repeat. August 28, 2014 at 3:13 pm

    These look amazing, definitely need to try them. Crispy sourdough and cheese sounds like the perfect sandwich to me.

  • Reply Ashley @ ashleymarieskitchen August 28, 2014 at 3:02 pm

    Yum! That croque monsieur looks amazing. I can’t wait to give this recipe a try 🙂

  • Reply Allison August 28, 2014 at 2:13 pm

    Oh my! These look incredible! I’ve got an abundance of sage in the garden that I was looking to put to good use too! Can’t wait to try these.

  • Reply Cheryl August 28, 2014 at 1:29 pm

    A prosciutto package! How more amazing could these get?!

    Spoiler: not much. It’s just simply not possible.

    Beautiful as always!

  • Reply Aysegul - Ice August 28, 2014 at 12:50 pm

    oh my yum! I love croque monsieur and this version looks amazing.
    I have got to make this in my kitchen very soon. PINNED!

  • Reply David @ Spiced August 28, 2014 at 12:24 pm

    I can’t say that I’ve ever had a Croque Monsieur, but I clearly need to fix that problem ASAP! These look absolutely delicious!

  • Reply Sarah@WholeandHeavenlyOven August 28, 2014 at 12:12 pm

    Holy YUM! These look like the best thing EVER! Seriously, these are sounding so good to me right now, I may just want them for breakfast. Super-gorgeous photos, Thaila!

  • Reply Ceara @ Ceara's Kitchen August 28, 2014 at 11:52 am

    You had me at crispy sourdough bread 🙂 These look wonderful! I am living in the heart of rich European cuisine so this sandwich could definitely be arranged for when that comfort food craving calls!

  • Reply Maureen | Orgasmic Chef August 28, 2014 at 11:40 am

    What a clever little sandwich and nothing like the croque monsieur my grandmother made for me as a chile. Looks amazing!

  • Reply Becca from It's Yummi! August 28, 2014 at 11:08 am

    Oh my goodness! I’ve heard of these amazing sandwiches, but until now, I had never seen one. Your perfect description and amazing photos are making me want one immediately!

  • Reply Nagi {REcipetin eats} August 28, 2014 at 10:17 am

    holy moly moly!!! Croque Monsier is one of my ALL TIME favourite foods. When I pass, I want to be buried under a pile of Croque Monsiuer – preferably these ones!! AAGGH, I can’t tell you how much I am DROOLING right now, especially while I’m preparing a bland boring quick dinner!!

  • Reply Lisa@Bakebellissima August 28, 2014 at 9:04 am

    This looks divine! I haven’t had croque monsieur in ages, this recipe brings back memories and I will have to try it very soon!

  • Reply Léa {tangerine zest} August 28, 2014 at 8:14 am

    Hey Thalia.
    Thanks for your message in my blog. Because of this, I discovered your blog and I’m in love with it !
    I love your version of the ‘croque monsieur’ !
    See u

  • Reply EriN August 28, 2014 at 7:45 am

    Yum! These look so delish.

    I’m making blue cheese burgers this weekend and was going to make a little onion jam for them- so I’m going to use this recipe!

  • Reply Ansh August 28, 2014 at 5:21 am

    So you heard it before!! But here goes .. I have never seen a croque monsieur this sexy!! Oh drooliicously good!!

  • Reply Cindy @ Pick Fresh Foods August 28, 2014 at 3:08 am

    These little croque monsieurs look so delicious! I’m already dreaming of the crsipy, oozy deliciousness! Pinning

  • Reply Kathy @ olives & garlic August 28, 2014 at 2:29 am

    Drool. Pinning, amazing!!!!

  • Reply Emily August 28, 2014 at 1:58 am

    Yum! Something definitely worth indulging in. 🙂 Love the little bundles you made. Such pretty presentation!

  • Reply Gayle @ Pumpkin 'N Spice August 28, 2014 at 1:57 am

    What a great recipe, Thalia! The french onion relish sounds amazing! Love the presentation of these cuties!

  • Reply Liz August 28, 2014 at 1:26 am

    I love your bite sized croque monsieurs! I always have Grueyere in my fridge…and I even have some leftover prosciutto 🙂 Wonder if I can whip these up without running to the market…might be my lucky day 🙂

    • Reply thalia August 28, 2014 at 1:32 am

      I hope you try the recipe Liz!

  • Reply marcie August 28, 2014 at 12:27 am

    I love that you wrapped these sandwiches with crispy prosciutto like delicious little presents! I love Croque Monseiur, and it sounds so tasty with that relish. Pinning!

    • Reply thalia August 28, 2014 at 1:32 am

      Love it, thanks Marcie!

  • Reply Nguyet @ taming of the spoon August 28, 2014 at 12:13 am

    Wow! These look amazing. I am writing up my grocery list right now and the ingredients for this recipe just got added. I’ll let you know how they turn out.

  • Reply Danielle August 27, 2014 at 11:53 pm

    This looks so perfect and delicious, I could definitely go for one of these right about now!

  • Reply Ahu @ ahueats August 27, 2014 at 11:48 pm

    I’ve never seen such a chic croque monsieur before – usually they’re a giant oozy mess (granted DELICIOUS). Beautiful!

    • Reply thalia August 27, 2014 at 11:51 pm

      I agree Ahu, I like to have a more ‘refined’ croque sandwich. Thanks for stopping by!

  • Reply sippitysup August 27, 2014 at 10:50 pm

    THis is about the most adorable presentation I’ve ever seen on a croque. GREG

    • Reply thalia August 27, 2014 at 11:35 pm

      Thanks Greg!

  • Reply Emma August 27, 2014 at 10:06 pm

    Oh they look so crispy! And I love the French onion relish – delicious little treats all round.

  • Reply Baby June August 27, 2014 at 10:01 pm

    Wow, that looks amazing! I just love the French onion relish, mmm 🙂

  • Reply John@Kitchen Riffs August 27, 2014 at 9:54 pm

    I love croque monsieur! And this is such a fun and creative take on this classic. Really good stuff — thanks so much.

  • Reply Jennifer @ Seasons and Suppers August 27, 2014 at 9:34 pm

    Absolutely stunning! Love every part of this 🙂

    • Reply thalia August 27, 2014 at 9:35 pm

      Thanks Jennifer!

  • Reply Caroline @ Shrinking Single August 27, 2014 at 9:17 pm

    One of my favourite breakfasts to have when I eat out so will have try making these. They look fab and love the string keeping everything together.

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