Cook onions and celery in 4 tablespoons butter 10 minutes.
Cut cabbage (1 pound) lengthwise and add with parsley. Cook covered 10 minutes. Stir in flour and cook 2-3 minutes. Stir in stock and cook 30 minutes.
Saute mushrooms in 1 tblsp oil. In last 10 minutes add mushrooms and peas and cooked sausage slices.