Peel, wash and cut the kohlrabi into pieces. Peel and finely chop the onion.
Heat 2 tablespoons of fat in a saucepan. Fry the onion until transparent. Add kohlrabi and steam briefly. Season with salt and pepper. Dust with flour and sauté briefly. Stir in about 1 l water and stock, bring to the boil.
Cover and simmer for 15-20 minutes.
Cut the toast into small cubes. Heat 2 tablespoons of fat in a frying pan. Fry the bread cubes in it while turning them golden brown. Season with salt and paprika and take out. Wash the cress and cut from the bed.
Stir half of the cress into the soup, puree everything finely. Stir in 100 g crème fraiche. Season soup with salt, pepper and 1 pinch of sugar. Serve the kohlrabi cress soup. Serve with 1 teaspoon each of crème fraîche, croutons and remaining cress.