Croque Monsieur

Ingredients

• Unsalted butter (4 tablespoons, divided)
• All-purpose flour (2 tablespoons)
• Milk (1 cup)
• Nutmeg (1/4 teaspoon)
• Salt (1/2 teaspoon)
• Black pepper (1/4 teaspoon)
• Dijon mustard (4 tablespoons)
• White bread (8 slices)
• Sliced ham (8 ounces)
• Gruyère cheese, grated (1 cup)

Instructions

1. Preheat the oven to 400°F (200°C).
2. In a small saucepan, melt 2 tablespoons of the butter over medium heat. Once melted, add the flour and cook, stirring constantly for about 1 minute until it forms a smooth paste (roux).
3. Gradually whisk in the milk, continuing to stir until the sauce thickens, approximately 5 minutes. Remove from heat and stir in the nutmeg, salt, pepper, and 1/2 cup of the grated Gruyère cheese until smooth.
4. Spread the remaining 2 tablespoons of butter evenly on one side of each slice of bread. On the unbuttered side of 4 slices, spread Dijon mustard. Layer on the sliced ham and top with the remaining Gruyère cheese. Cover with the other 4 slices of bread, butter side up.
5. In a large skillet over medium heat, add the sandwiches and cook until golden brown on both sides, about 5 minutes per side. You may need to press down gently with a spatula for even toasting.
6. Transfer the sandwiches to a baking sheet. Generously spread the béchamel sauce over the tops of the sandwiches and sprinkle with the remaining Gruyère cheese.
7. Bake in the preheated oven until the cheese is melted and bubbly, about 10 minutes. For extra crispiness, you can broil for an additional 1-2 minutes, keeping a close eye to avoid burning.
8. Allow to cool slightly before slicing and serving.