Mushrooms are cleaned and cut into slices. Boil in salted water with carrots, onion and black pepper. After straining boil and remove vegetables and black pepper. Fry flour in the butter and dilute to moderately thick sauce broth of mushrooms. Add the egg yolks beaten with yogurt. Finally add the mushrooms. Dish boil 3-4 minutes on low heat, stirring. Serve hot, sprinkled with chopped parsley.