Boil potatoes unpeeled, then peel. Hard boil eggs and remove shell.
Cut sausage into thin slices, cooked potatoes and eggs into normal slices. Grease a deep and large enough baking dish or casserole dish with butter. Layer in ingredients: Potatoes, sausage, salt and pepper, parsley, potatoes, eggs, salt and pepper, parsley, potatoes … the top layer should be slightly thicker and consist of potatoes. There should be at least 2 layers each of sausage and eggs. Mix cream, sour cream and milk to a homogeneous mass (should have a slightly thicker consistency like pure cream, but not too thick!
If necessary, vary the amount of milk), season with salt and pepper, mix in about 1 – 2 tbsp.
chopped parsley and pour the whole thing over the casserole.
Cover the casserole dish and bake in a preheated oven at 200 – 225 °C for 60 minutes. In the last 10 minutes, remove the lid to give the dish a nice golden color. Serve with a salad of the season.