Soak the beans overnight in three times the amount of water. Drain the water the next day, but collect it.
Heat the lard in a saucepan. Peel and dice the onion and sweat it in the lard. Add the beans with the water. Add the bay leaf, marjoram, savory and a little pepper and let it boil, do not add salt yet.
In the meantime, peel, wash and dice the potatoes. Clean, wash and cut the soup greens.
When the beans are almost soft, add the potatoes and soup greens and season everything with salt and pepper.
Cut the sausages into slices and let them steep in the hot soup for a few minutes.
Let the slices of the Mettendchen cook for a few minutes, this makes the soup even more flavorful.