French Béchamel Ham and Gruyère Croque Monsieur

Preheat the oven to 200°C. Use 120 g ready-to-eat fully cooked ham and grate 160 g cheese, reserving half for inside and half for the tops.

Melt 22 g butter over medium-low heat and whisk in 22 g flour for 1–2 minutes. Slowly whisk in 180 ml milk and cook 3–5 minutes until lightly thickened and coating a spoon. Add 0.5 g nutmeg and 1 g salt.

Spread 15 g mustard among four bread inner faces. Distribute half the béchamel, 120 g ham and 80 g cheese between two sandwiches, and lightly butter exteriors with remaining 8 g butter.

Toast sandwiches in a skillet over medium heat for 2–3 minutes on each side until golden. Transfer to an oven tray and spoon remaining béchamel and 80 g cheese evenly over the tops.

Bake at 200°C for 8–12 minutes until heated through and cheese is melted. If needed, broil 1–2 minutes under constant observation for golden tops. Serve two hot sandwiches.