Classic Croque Monsieur

Step 1
Preheat the oven to 400 degrees F (200 degrees C). Line a baking sheet with parchment paper.

Step 2
Combine milk and cream in a microwave-safe container and microwave on high power, about 90 seconds. The liquid should be warm to the touch.

Step 3
Melt butter in a small saucepan over medium heat. Stir in flour and keep stirring until all the flour is coated in butter, and the flour and butter begin to bubble, about 2 minutes. Gradually stir in warmed milk and cream and cook until sauce begins to thicken, stirring constantly. Continue stirring, until the sauce is thick and bubbly, 3 to 5 minutes. Remove from heat and season with salt, pepper, and nutmeg. Set aside.

Step 4
Melt 1 tablespoon butter in a large skillet over medium heat and brown 4 pieces of bread on 1 side, about 4 minutes. Place browned bread on the prepared baking sheet, browned side down.

Step 5
Spread each piece of bread with Bechamel sauce, from edge to edge. Place two slices of deli ham on the Bechamel and top with 1/2 cup of grated Gruyere cheese. Place remaining bread slices on top of each sandwich and spread the top with Bechamel, from edge to edge. Sprinkle the top of each sandwich with 2 tablespoons grated Gruyere cheese and 2 tablespoons grated Parmesan cheese.

Step 6
Bake in the preheated oven until the cheese is melted, 5 to 7 minutes.

Step 7
Turn on the oven's broiler.

Step 8
Move baking sheet about 6 inches from the heat source and broil sandwiches until the top is bubbly and brown, 2 to 3 minutes. Watch carefully, to avoid scorching the parchment paper and burning the cheese. Allow the sandwiches to cool slightly, cut in half, and serve warm.