Peel and roughly dice the onion. Clean, wash and cut the leek into coarse rings. Heat 1 tablespoon of oil in a roasting pan. Fry the meat in 2 portions, turning vigorously. Remove the meat. Sauté onion and leek in frying fat.
Add meat again, dust with flour, sweat briefly and deglaze with cider and stock. Wash the marjoram, shake dry. Add about half to the goulash. Stew goulash covered for about 1 1/2 hours at low heat.
Form potato dough into a roll (6-7 cm Ø), cut into approx. 8 slices. Press each slice slightly flat. Cover each slice with 1 mettball and form into a dumpling. Pour into boiling salted water, cook for 15-20 minutes
Add apples to goulash. Add 2 tablespoons of oil to the frying set. Fry the mushrooms for about 5 minutes, turning them and add them to the goulash. Stir mustard into the goulash, season with salt and pepper.
Drain the pasta and put it back into the pot. Add fat to the noodles, melt and mix. Arrange goulash and noodles on plates. Garnish with remaining marjoram.