Peel and wash the potatoes and carrots and cut them into small cubes. Clean, wash and cut cabbage into pieces. Boil the potatoes and carrots in the stock and cook for 15 minutes. Add cabbage for the last 5 minutes. Heat the oil in a pan.
Press the sausage into the hot oil and fry all around. Rinse cress. Add meatballs to the soup. Season to taste with salt and pepper. Cut cress from the bed and sprinkle over the carrot-potato soup