Peel, wash and halve the potatoes and cook in boiling salted water for about 20 minutes. Clean the savoy cabbage and cut out the stalk. Cut cabbage into small pieces, wash and drain. Cook in boiling broth for about 5 minutes, drain and catch the broth. Finely dice the bacon and leave it crispy in a pan without fat. Set aside.
Fry sausages in hot oil while turning for 6-8 minutes. For the sauce, peel and chop the onion. Wash the chives and cut into small rolls. Fill up broth with water to 1/2 liter. Bring vinegar and onions briefly to the boil. Add stock and milk, bring to the boil and remove from the heat. Sprinkle in puree powder and let it swell out a little. Stir in chives and bacon. Season to taste with salt, pepper and sugar. Shortly before serving, fry the savoy cabbage in bacon fat and some melted butter for about 5 minutes. Season with pepper from the mill.
Add stock and milk, bring to the boil and remove from the heat. Sprinkle in puree powder and let it swell out a little. Stir in chives and bacon. Season to taste with salt, pepper and sugar. Shortly before serving, fry the savoy cabbage in bacon fat and some melted butter for about 5 minutes. Season with pepper from the mill. Arrange everything on plates garnished with parsley. Serve with grainy mustard