Finely slice the bread, season it and pour boiling milk over it. Finely dice the Black Forest Ham and the onion, saute a little, add to the bread and mix well with the eggs. (If the mixture is a little too soft, add enough flour so that the mixture is dry but still easy to form.
Wet your hands and form evenly sized dumplings. Steep them under the boiling point in salted water for at least 10 minutes. Take the dumplings out of the water, cut them in half and place them one after the other in a gratin dish, cover them with the light sauce (béchamel), sprinkle them with cheese and bake them in the oven at a higher heat.