This Decadent Sandwich Is a Cross Between Monte Cristo and a Croque Monsieur

There are many lovely carbs I enjoy using as sandwich bread—including pancakes and french toast—but oddly, I rarely use croissants. I prefer to eat those fresh and they’re far too flaky to hold a hearty sandwich together (and I only eat hearty sandwiches). However, day-old croissants, or store-bought packaged croissants are a different story. The crisp flakes have humidified, and instead you have a pocketed buttery bread with a tough eggy skin; the perfect structure for a decadent croque monsieur. 

If you haven’t met a croque monsieur before, it’s an elevated ham and cheese sandwich of French origin. It’s usually composed of two crusty sourdough slices, Gruyère cheese, ham, and a smear each of dijon and béchamel sauce. The whole sandwich is toasted until crisp, melty, and golden brown in a buttery pan. Add an egg on top and now you have a croque madame. I told you it was elevated.

Croissants aren’t crusty in the sense that sourdough loaves are crusty, but personally, that’s part of the allure. Sometimes I don’t want eating to be hard work, and that half-inch thick crust is a proper chewing challenge. Aged croissants are buttery, with flaky pockets, and for some sick, deranged reason, I am under the impression that croque monsieurs should be made like French toast. Meaning those airy pockets get filled with creamy custard. Inexplicably, I think I married it with a Monte Cristo or mozzarella in carrozza (which can and should be made in your air fryer), but you know what, this quick soak gives stale croissants new life. That said, if you want to skip the custard bath, you totally can.

How to make a Croissant Monsieur

1. Soak your croissant in custard

Whisk a bit of cream with an egg and salt. Split the croissant in half equatorially and dunk it in the custard to soak up the mixture. Fry the halves in a buttered frying pan just until all sides are lightly browned. Take the pieces out and let them cool briefly on a wire rack. 

Credit: Allie Chanthorn Reinmann

As I mentioned, this step is optional since it is my perverted croque-cristo-carrozza fantasy, but I highly suggest it. The custard creates a soft, spongy texture with the bread that I adore. Skip to step two if you’re not interested or you just want to save time. The sandwich will be crisper without the custard.

2. Make the béchamel sauce

Whipping up a small amount of béchamel sauce is easier than it sounds. Heat a quarter cup of milk in the microwave until steaming. Whisk a pat of butter and a tablespoon of all-purpose flour in a small pot until the butter is melted and the mixture has been bubbling for about a minute. While whisking continuously, slowly pour in the warm milk. Turn off the heat and add a pinch of salt and nutmeg. 

Credit: Allie Chanthorn Reinmann

3. Build the sandwich

Spread some of the béchamel sauce onto each side of the croissant. Add shredded or thinly sliced Gruyère or swiss cheese on top of the creamy sauce, then add one or two slices of ham. Spread some dijon on the ham and close up the sandwich.

4. Fry it 

In the same buttery pan, add a tad more butter and place the sandwich inside. I topped my sandwich with more cheese, but if you plan to flip it then don’t. Put a lid on top and heat the sandwich over medium-low to heat the sandwich through and melt the cheese. After three to five minutes, flip the sandwich to toast the other side. If you’re not flipping it, take it out once the cheese has melted.

Credit: Allie Chanthorn Reinmann

This croissant monsieur is a Level 10 for decadence. The béchamel sauce nestled next to the cheese creates a creamy, stretchy sensation and the outer croissant that was fried in butter is tender but still provides a welcome crisp texture. This sandwich is best enjoyed right away.

Croissant Croque Monsieur Recipe

For the béchamel sauce

For the sandwich

• 1 egg

• ½ cup cream

• ½ teaspoon salt 

• 2 croissants (day-old or packaged are best), split

• 1 teaspoon of butter

• ½ cup shredded or shaved Gruyère cheese (or any Swiss cheese)

• 2 slices of ham

• Dijon mustard, to taste

1. Make the bèchamel sauce by adding the butter and flour to a small pot over medium heat. Whisk until the mixture bubbles for about a minute, then slowly whisk in the milk until a thick sauce develops. Mix in the salt and nutmeg. Set aside.

2. Melt the teaspoon of butter in a frying pan over medium-low heat. Whisk the egg, cream, and salt in a bowl. Dunk the croissant halves into the custard and add them to the frying pan. Fry them until all sides have lightly browned. Remove the croissants from the pan to a wire rack.

3. Spread the béchamel sauce onto the croissant halves, add the cheese, ham, and a bit of dijon mustard. Close the two sandwiches and put them back in the frying pan. Top them with a little extra cheese if you like and put a lid on the pan. Fry them over medium-low heat until the bottoms are toasty and the cheese in the center is melted. Enjoy immediately.