Peel and chop the onion. Cut the sausage into slices. Clean, wash and cut the bell peppers into strips.
Heat the oil in a pot. Fry the sausage and onion in it. Add strips of paprika, sauerkraut and sweet paprika and fry. Pour in just under 1 l water and bring to the boil. Cover and simmer for about 10 minutes.
In the meantime, clean and wash the spring onions and cut them into rings. Add the spring onions and marjoram and continue cooking for about 5 minutes. Season to taste with salt and pepper. Serve soup with sour cream.