Classic Croque Monsieur Bake

Prepare the Béchamel Sauce

1. 1Melt butter in a medium saucepan over medium heat. Whisk in flour and cook for 1-2 minutes, stirring constantly, until a thick paste (roux) forms.
2. 2Gradually whisk in the warm milk, a little at a time, until smooth. Continue whisking until the sauce thickens to a creamy consistency, about 5-7 minutes.
3. 3Stir in nutmeg, salt, and pepper. Remove from heat and set aside.

Assemble the Croque Monsieur

1. 1Preheat your oven to 200°C (390°F).
2. 2Spread Dijon mustard on one side of half the bread slices (4 slices).
3. 3Place a layer of ham on the mustard-covered bread, then sprinkle with a generous amount of Gruyère cheese.
4. 4Top with the remaining bread slices to form sandwiches.
5. 5Lightly butter the outside of each sandwich if desired (optional for grilling).

Bake the Croque Monsieur

1. 1Heat a large skillet or griddle over medium heat. Place the sandwiches in the skillet and grill for 2-3 minutes per side, until golden brown.
2. 2Arrange the grilled sandwiches in a single layer on a baking sheet.
3. 3Spoon a generous amount of béchamel sauce over the top of each sandwich, ensuring full coverage.
4. 4Sprinkle the remaining Gruyère cheese over the béchamel sauce.
5. 5Bake for 10-15 minutes, or until the cheese is melted and bubbly and the tops are golden brown.
6. 6Serve immediately, perhaps with a simple green salad.