Peel the kohlrabi and potatoes and cut into cubes. Sweat both in a little butter in a saucepan. Cover with water and simmer.
Shape the minced meat into dumplings and add. Add half a cup of cream, vegetable stock, salt and pepper and cook for another 25 minutes. Add the rest of the cream. Mix the starch with cold water and bind the dish with it until it has about the consistency of a cream soup, maybe a little more liquid.