Wash the potatoes and cook them covered in plenty of boiling water for about 20 minutes. Wash apples, cut into quarters, remove core. Cut apples into slices. Peel onions and cut into strips.
Drain the potatoes, peel them and press them through a potato ricer. Add egg and starch to the potatoes and mix. Season to taste with nutmeg and salt. Form 12 dumplings from the potato dough. Boil up plenty of salted water.
Add the dumplings and let them simmer for 15-20 minutes at low heat until they rise to the surface. Remove the dumplings. Heat the fat in a pan. Brown the dumplings all around. Dab meat dry and bind with kitchen string.
Heat the oil in a pan. Fry the steak for 6-8 minutes while turning and keep warm. Fry apples and onions in the frying fat for about 3 minutes. Deglaze with white wine and stock and bring to the boil. Bind with sauce thickener and bring to the boil again.
Season with salt, pepper and marjoram. Arrange steaks, dumplings and apple-onion sauce on plates. Garnish with marjoram.