Stew sauerkraut, stirring in some water, fine chopped onion and carrot cut into stripes, until sauerkraut soft.

Cook mushrooms, drain excess liquid, and slice. Filter the broth, add sauerkraut, mushrooms, parsley and celery roots cut into stripes.

Fry flour for a while, and then stir in the mushroom broth just enough to become the consistence of sour cream.

Add flour dressing to the sauerkraut soup. Season with salt, sugar, bring to a boil, transfer from the heat, and leave to stand. Sprinkle with fine chopped greens when serving.