How to Make Croque Monsieur

Croque monsieur is a French grilled ham and cheese sandwich built with bechamel sauce and Gruyere, baked or broiled until the top turns golden and bubbling. You make a quick bechamel, layer it with ham and cheese between slices of bread, and finish the whole thing under heat rather than just in a pan.

It first appeared in Parisian cafes in the early 1900s as a quick, filling lunch that could be made fast for the after-work crowd. The name translates loosely to 'crunchy mister,' a nod to the sandwich's crisp, toasted exterior. Add a fried egg on top and it becomes a croque madame instead.

It looks like an ordinary grilled cheese sandwich, but the bechamel is what actually sets it apart and makes it worth the extra ten minutes.

What Actually Matters

The bechamel is the step people skip, and it's the one that matters most. A basic ham and cheese sandwich toasted in a pan is not a croque monsieur, it's just a grilled cheese. The bechamel adds richness and moisture that keeps the inside creamy while the broiler crisps the top, and it's what gives the sandwich its identity.

Croque Monsieur Recipe

Serves 4 | Prep time: 15 minutes | Cook time: 15 minutes | Total time: 30 minutes

Ingredients

2 tablespoons unsalted butter
2 tablespoons all purpose flour
1 cup whole milk
1/4 teaspoon ground nutmeg
Salt and black pepper, to taste
8 slices sandwich bread
1 tablespoon Dijon mustard
8 ounces sliced ham
1.5 cups shredded Gruyere cheese
2 tablespoons grated Parmesan cheese

Method

Preheat the oven to 400 degrees F and set the broiler ready for the final step.
Melt the butter in a small saucepan over medium heat. Whisk in the flour and cook for 1 minute.
Slowly whisk in the milk and cook, whisking constantly, until thickened, about 4 minutes. Stir in the nutmeg, salt, and pepper.
Spread the mustard lightly over 4 slices of bread. Layer with ham and a third of the Gruyere, then top with the remaining 4 slices of bread.
Place the sandwiches on a baking sheet and spread the bechamel evenly over the tops.
Sprinkle the remaining Gruyere and the Parmesan over the bechamel.
Bake for 10 minutes, then switch to broil for 2 to 3 minutes, until the tops are golden and bubbling.
Let cool for 2 minutes before slicing and serving.

Nutrition (per serving, estimated)

Calories	Protein	Fat	Carbs
490	27g	28g	32g

This is a calculated estimate based on standard ingredient values, not a lab-verified figure.

Tips and Variations

Top each sandwich with a fried egg after baking to turn it into a croque madame. Use a good sturdy sandwich bread, since thin sliced bread can get soggy under the bechamel. A nonstick saucepan makes the bechamel step much easier to manage without scorching.

These are best eaten fresh out of the oven, but you can assemble the sandwiches (without the bechamel on top) a few hours ahead and refrigerate until ready to bake.