Ham and Gruyère Croque Monsieur

Preheat your oven broiler to high.

Melt 15g of butter in a small saucepan over medium heat, stir in the flour, and cook for 1 minute until fragrant.

Gradually whisk in the milk, bringing the mixture to a simmer until thickened into a smooth bechamel sauce, then season with salt, pepper, and a pinch of nutmeg.

Spread Dijon mustard on two slices of bread, layer with half the ham and half the grated Gruyère, then top with the remaining bread slices.

Melt the remaining 15g of butter in a skillet over medium heat and toast the sandwiches for 2 minutes per side until golden brown.

Place the toasted sandwiches on a baking sheet, spread the bechamel sauce generously over the top of each, and sprinkle with the remaining cheese.

Broil for 3 to 4 minutes until the cheese is melted and bubbling with golden brown spots.