👨‍🍳Instructions

1. 1

   Prepare the Béchamel Sauce: In a small saucepan, melt 2 tablespoons of unsalted butter over medium heat. Add 2 tablespoons of flour and whisk continuously for 1-2 minutes to form a roux; do not let it brown. Gradually whisk in the warm milk, a little at a time, ensuring no lumps form. Continue whisking until the sauce thickens and coats the back of a spoon, about 5-7 minutes. Season with a pinch of freshly grated nutmeg, salt, and pepper. Remove from heat and set aside.

2. 2

   Assemble the Sandwiches: Lightly butter one side of each bread slice. If using, spread a thin layer of Dijon mustard on the unbuttered side of two bread slices. On the mustard/unbuttered side of these two slices, layer half of the grated Gruyère, then two slices of ham, then another quarter of the Gruyère. Place the remaining two bread slices (buttered-side up) on top to form two sandwiches.

3. 3

   Grill the Croque Monsieurs: Heat a large non-stick frying pan or griddle over medium heat. Place the sandwiches in the pan, buttered-side down. Cook for 3-4 minutes per side, until golden brown and the cheese inside begins to melt.

4. 4

   Add Béchamel and Finish: Remove the partially grilled sandwiches from the pan. Carefully spoon a generous amount of béchamel sauce over the top of each sandwich, spreading it to cover completely. Sprinkle the remaining grated Gruyère over the béchamel. Place the sandwiches on a baking sheet and bake in a preheated oven at 200°C (400°F) for 8-10 minutes, or until the béchamel is bubbly and golden brown. If you have a broiler, you can broil for the last 1-2 minutes for a crispier, browned top (watch carefully to prevent burning).

5. 5

   Serve: Let the Croque Monsieurs rest for a minute before serving hot, perhaps with a simple green salad.