For the Schwammerlgulasch, sauté the onion in a large pot. Sprinkle with paprika powder and stir briefly.
Deglaze with vinegar, add the mushrooms (not too small) and season with salt, pepper and a little sugar. Stew for about 10 minutes.
Then add the parsley. In a bowl, mix the sour cream with a dash of cream and the flour until smooth.
Just before serving, add the sour cream and bring to the boil for the last time.