Peel and finely dice the onion and garlic. Peel, wash and finely dice the kohlrabi. Wash and finely dice the zucchini. Heat oil in a pot, fry onion and garlic.
Add vegetables and sauté briefly. Season with salt and pepper. Deglaze with broth, bring to the boil, cover and cook for about 12 minutes. In the meantime cut bread into small lozenges. Melt butter in a small pan.
Add the bread wedges and roast on low heat while turning. Remove from the pan. Cut the cress from the bed. Remove 1 tbsp. vegetable cubes from the stock and drain. Finely puree the remaining vegetables in the stock.
##Stir in sour cream, season again with salt, pepper, sugar and nutmeg. Arrange in small bowls with diced vegetables, croutons and cress. Add remaining cress and croutons separately.