For the potato and egg gratin, cut the potatoes, cooked in their skins, into slices. Hard-boil two eggs and cut them into slices as well. Prepare a bechamel sauce with skim milk, butter and flour and let it cool down. Season with salt, pepper and nutmeg. Then add 2 egg yolks, sour cream and half the amount of cheese.
Beat the egg whites until firm and fold them in. A greased ovenproof dish is sprinkled with breadcrumbs. Add the sliced potatoes and eggs to the prepared sauce. Pour the potato-egg mixture into the dish, sprinkle with grated cheese and bake the potato-egg gratin in the oven at 180°C for about 30 minutes until light brown.