For the mushroom sauce, clean the mushrooms, depending on their size, leave them whole or cut them into small pieces.
Heat butter, sauté diced onion, add mushrooms, season with salt and pepper and stir.
Cover and cook for about 10 minutes until soft, drain off the liquid. Add cream.
Stir sour cream with flour and add to mushrooms. Finish with parsley, salt and pepper.
Serve with bread dumplings and fresh parsley.