The Best Croque Monsieur Recipe Ever

Prepare the Béchamel Sauce: In a small saucepan over medium heat, melt 30g butter. Whisk in flour and cook for 1–2 minutes to create a light roux. Gradually whisk in the milk until smooth. Simmer until thickened, then remove from heat and stir in 50g of Gruyère, nutmeg, salt, and pepper.

Toast the Bread: Preheat oven to 200°C (400°F). Butter both sides of the 8 bread slices using 60g of softened butter. Place on a baking sheet and toast for 3–5 minutes per side until lightly golden.

Assemble the Sandwich: Lay 4 slices of toasted bread on the baking sheet. Spread a thin layer of Dijon mustard on each. Top with ham and a portion of the grated Gruyère. Place the remaining 4 bread slices on top.

Apply Topping: Spread a thick layer of the prepared Béchamel sauce over the top of each closed sandwich, ensuring it reaches the edges. Sprinkle the remaining Gruyère cheese over the sauce.

Bake and Broil: Bake at 200°C (400°F) for 5 minutes. Switch to the broiler setting for 2–3 minutes until the cheese is bubbling and browned. Serve immediately.