Peel, wash and roughly dice the potatoes. Peel onion and cut into cubes. Heat oil in a pot. Fry potatoes and onion. Stir in a good 3/4 l water and stock. Bring to the boil and simmer for about 20 minutes
Clean, wash and chop the beans. Cook in little boiling salted water for about 12 minutes. Drain
Finely mash the potatoes in the broth. Stir in the cream. Wash and pluck the marjoram. Finely dice the Kasseler. Add beans and marjoram to the soup. Season to taste with salt and pepper.