1 Peel potatoes, carrot, onion and kohlrabi and cut all into small cubes. Cut the leek lengthwise, rinse and cut into narrow rings. Rinse celery, trim and cut into strips. Rinse the lentils through a sieve and drain well.
2 Peel the chorizo, cut into slices and fry in a pan with 1 tablespoon oil. Remove from pot and add the vegetables. Sauté briefly, turning occasionally. Add lentils, sauté briefly and pour in the stock. Add the bay leaf and season with salt, pepper and marjoram and simmer for about 30 minutes over medium heat.
3 Place the chorizo back into the pot and let the soup simmer for about 15 minutes.
4 Season the soup again and serve sprinkled with freshly chopped parsley.