Boil jacket potatoes, drain and immediately rinse with cold water. Then peel and cut into slices. Heat the margarine or clarified butter and fry the diced bacon and onion in it. Add the potatoes in portions and fry them. Possibly take a second pan, then it goes faster. Season with salt, marjoram, pepper from the mill and a little caraway seeds.
Put the potatoes in a greased baking dish. Stir the sour cream until smooth and pour over it. Cut the sausage into slices, cut large slices in half or quarter and place on the casserole. Whisk the eggs with milk, cream and chopped parsley. Do not add salt, as the sausage gives off enough salty taste to the casserole. Pour the egg milk onto the potato and sausage mixture.
Bake the casserole in the preheated oven at 200 ° for about 30-40 minutes on the middle rack.