Peel and finely dice the onion and garlic. Peel, wash and chop the potatoes and kohlrabi. Heat the oil in a pot. Fry onion and garlic. Add potatoes and kohlrabi and fry briefly.
Deglaze with vegetable stock and bring to the boil. Cook over medium heat for about 15 minutes. Remove the pot from the heat and let half of the ingredients drip off briefly on a skimmer and remove. Put aside.
Finely purify the remaining ingredients in a pot. Cut Cabanossi into slices. Add cabanossi, peas and vegetable pieces to the pot and cook for about 5 minutes. Arrange the stew on plates. Garnish with one teaspoon of sour cream and cress each.