Discard the outer savoy cabbage leaves, remove the stalk from the remaining savoy cabbage leaves and cut them into strips. Peel the potatoes and cut into small cubes (approx. 2 x 2 cm). Heat the butter in a saucepan, fry the finely chopped onion and the bacon cubes. Then add the savoy cabbage and the diced potatoes and pour on the broth (not all of it at first, half of it is often enough at the beginning, then gradually add the rest). Let the whole thing simmer with the lid closed for about 20 minutes over medium heat, stir in between, season with salt and black pepper. Bratwurst or a hearty roast goes well with it.