For the potato and kohlrabi soup, peel the potatoes and cut into rough cubes. Also peel and coarsely dice the kohlrabi.
Place both types of cubes in a pot and pour in enough soup to cover them well and cook until soft. While it is boiling, press the garlic into the soup.
When everything is soft, remove the pot from the heat and season with the spices. Puree everything well and add some soup if necessary or season a little more.