Stuffing: remove the skin from the onions, quarter them, chop them finely and fry them in oil. Cut cooked beef into pieces and put them through a meat grinder together with hard-boiled eggs. Add salt, onion, sour cream and pepper and mix.
Bake the pancakes as light as possible. Fill them with the mixture and fold them into rectangular packets.
Keep them in the refrigerator until you are ready to use them. Heat butter in a frying pan and bake the pancakes until golden brown.
Tip: It is best to use your favorite ham – then your dish will taste twice as good!