Meanwhile, peel and dice the onions. Fry the meat in a little butter in a frying pan and add half of the onions. Season to taste with the spices and set aside.
Now fry the remaining onions in 1 tablespoon of butter. Dust with flour, sweat briefly and then deglaze with the milk. Bring to a boil and simmer for about 5 minutes. Stir in the grated cheese and remove the sauce from the heat. Now whisk the eggs with the sour cream or sour cream and stir into the sauce. Season to taste with salt and pepper.
Peel and slice the jacket potatoes. 3/4 of the potatoes are placed in a greased high baking dish. The meat is spread over it and covered with the remaining potatoes. Now pour the cheese sauce evenly over it and bake the whole thing in a preheated oven at 200 degrees for 30 minutes.