Croque Monsieur

Melt 30 g of the butter in a small saucepan over medium heat. Add the flour and stir for 1 minute, without letting it colour. Add the milk a little at a time, whisking constantly, so that no lumps form. Cook for 8–10 minutes over medium-low heat, whisking, until the sauce is thick and smooth and coats the back of a spoon. Season with the nutmeg, salt and pepper, and take it off the heat.

• butter30 g
• wheat flour30 g
• milk400 mL
• nutmeg1 pinch
• saltto taste
• black pepperto taste

Grate the Gruyère. Lay 4 slices of bread on a board. Cover each with a slice of ham, then with 30 g of the grated Gruyère, keeping the cheese away from the very edges. Put the other 4 slices of bread on top and press down gently. Keep the remaining 80 g of cheese for the top. Trim the crusts if you like a neater sandwich.

• white bread8 slices
• cooked ham4 slices
• Gruyère cheese120 g

Heat the oven to 220 °C. Melt 10 g of the remaining butter in a large frying pan over medium heat and fry 2 sandwiches for 2–3 minutes on each side, until golden brown and crisp. Lift them onto a baking tray. Wipe the pan, add the last 10 g of butter and toast the other 2 sandwiches in the same way. Frying first seals the bread, so the béchamel does not soak in.

• butter20 g

Spread a generous layer of béchamel over the top of each sandwich, right to the edges. Sprinkle the remaining 80 g of grated Gruyère evenly over the sauce. Bake in the middle of the oven for 6–8 minutes, until the cheese has melted and is bubbling with golden spots. If you like a darker top, finish under the grill for 1 minute, watching closely. Serve straight away.

• Gruyère cheese80 g