For the kohlrabi soup, first peel the kohlrabi and cut into cubes, as well as the onions.
Sauté both in a high pot with olive oil for about 5 minutes.
Then pour in water and add the soup cube. Let the kohlrabi simmer until soft and then puree with a blender.
Finally, refine the kohlrabi soup with caraway seeds and sour cream and enjoy.