- SERVES 4 PEOPLE
 
- 15 MIN PREPARATION
 - 15 MIN COOKING
 
Ingredients:
8 slicescrusty white bread, cut 1cm thick95 gm(1/3 cup) Dijon mustard, plus extra to serve4thick slices leg ham300 gmGruyère, coarsely grated100 gmbutter, coarsely chopped 4 duck eggs Béchamel60 gmbutter, coarsely chopped60 gmplain flour, sieved250 ml(1 cup) milk30 gmfinely grated parmesanPinchfinely grated nutmeg
Method
- 01
 - For béchamel, melt butter in a saucepan over medium heat, stir in flour, cook until light golden (1-2 minutes), remove from heat. Meanwhile, heat milk in a separate saucepan over medium-high heat until simmering, then, whisking continuously, gradually add milk to butter mixture. Return to heat, stir until mixture just returns to the boil (3-4 minutes), stir in parmesan and nutmeg, season to taste, cover closely with plastic wrap and set aside until thick and cooled to room temperature.
 
- 02
 - Place four slices of bread on a work surface, spread with mustard, top with ham and Gruyère, sandwich with remaining bread.
 
- 03
 - Preheat grill to high. Melt half the butter in a large frying pan over medium heat until foaming, add sandwiches to pan and cook, turning once, until golden (2-3 minutes each side). Remove from pan, spread tops thickly with béchamel and transfer to a baking tray, then grill until golden (3-4 minutes).
 
- 04
 - Meanwhile, heat remaining butter in a large frying pan and fry eggs to your liking (3-4 minutes for soft yolks). Place an egg on each sandwich and serve hot with extra mustard on the side.