Pre heat the oven (240ºC thermostat 8). On a slice of bread sandwich slightly buttered, put a layer of bechamel, some grated cheese and half a slice of ham.
Close the croque monsieur with a second slice of bread sandwich and cover it with bechamel and grated cheese.
Put the croque monsieur in a plate, cover them with aluminium foil and let them cook for 15-20min. You can serve them with green salad and french fries.