1: Trim the edges of the slices of pancarrè and place them in a preheated oven at 180°C for about 5 minutes.
2: Spread a little butter on the toasted slices of pancarrè and arrange them in a rectangular baking dish.
3: Top each slice of bread with a bit of prosciutto, a slice of cheese, and some pieces of fontina.
4: Cover each slice of pancarrè with another slice to form a sort of sandwich.
5: Prepare the béchamel sauce, and while it is still warm, mix in the grated Parmigiano Reggiano until well combined.
6: Pour the béchamel with Parmigiano over the 'sandwiches' in the baking dish.
7: Bake at 180°C for about 10 minutes until a golden crust forms on top.
8: Serve always hot and gooey.
