Croque Monsieur is a classic French sandwich that consists of ham and cheese, typically Gruyère or Emmental, sandwiched between slices of crusty bread. The sandwich is then topped with a béchamel sauce and grated cheese before being baked or broiled until it's golden and bubbly. It's a delicious and indulgent treat that's popular in French cafes and bistros. Here's a basic recipe for Croque Monsieur:

Ingredients:

8 slices of bread (traditionally pain de mie or brioche)
Dijon mustard
8 slices of ham
8 slices of Gruyère or Emmental cheese
Butter for spreading
Béchamel sauce (see below)
Grated Gruyère or Emmental cheese for topping

For the Béchamel Sauce:

2 tablespoons butter
2 tablespoons all-purpose flour
1 1/2 cups milk
Salt, pepper, and nutmeg to taste

Instructions:

For the Béchamel Sauce:

Make the Roux:

In a saucepan, melt the butter over medium heat. Add the flour and stir continuously to create a roux. Cook for a minute or two until the roux is light golden in color.

Add Milk:

Gradually whisk in the milk, ensuring there are no lumps. Cook the mixture over medium heat, stirring constantly, until it thickens and comes to a gentle boil.

Season:

Season the béchamel with salt, pepper, and a pinch of nutmeg. Remove from heat and set aside.

For the Croque Monsieur:

Preheat the Oven:

Preheat your oven's broiler.

Assemble the Sandwiches:

Spread Dijon mustard on one side of each slice of bread. Place a slice of ham and a slice of cheese on half of the bread slices. Top with the remaining slices of bread to create sandwiches.

Add Béchamel:

Spread a thin layer of béchamel sauce on top of each sandwich.

Top with Cheese:

Sprinkle grated Gruyère or Emmental cheese over the béchamel layer.

Broil:

Place the sandwiches under the broiler until the cheese is melted, bubbly, and lightly golden brown. Keep an eye on them to prevent burning.

Serve:

Remove from the oven and let them cool for a moment before serving. Croque Monsieur is often served warm and can be accompanied by a simple green salad.