Peel the potatoes, wash and cut into cubes the size of 2 centimeters. Peel cucumber, cut into slices. Clean mushrooms. Wash green onions, cut into slices 2 centimeterslong. In a saucepan melt the butter and fry the potatoes for 2 minutes, add the mushrooms, cook for a minute, add the onion and cucumber, pass until transparent. Pour vegetable broth and cook on low heat for 15-20 minutes (until tender potatoes). Wash herbs, dry and chop, add to the stew with sour cream and season with paprika, pepper and cumin and salt.