Clean, wash and halve the mushrooms. Peel onion and cut into rings. Cut the sausage into slices. Wash parsley, dab dry and chop finely, except for something to garnish.
Cook the dumplings in lightly boiling salted water at low heat for about 5 minutes. Mix sauce powder and 1/4 litre water well. Heat oil in a pot and fry mushrooms. Add sausage and fry.
Deglaze with sauce and bring to the boil. Stir in crème fraîche, simmer for 1 minute, add 3/4 of the parsley and season with salt and pepper. Drain the fat in a pan and fry the onion rings in it.
Quench dumplings cold and remove from the cooking bags. Arrange two dumplings on each ragout and serve sprinkled with onion rings and parsley. Garnish with the remaining parsley.