Peel, wash and halve the potatoes and cook in boiling salted water for about 20 minutes. Heat the oil in a pan. Fry the sausages in it at medium heat for about 10 minutes while turning.
Wash the marjoram, shake dry, pluck the leaves from the stalks and chop them except for something to sprinkle on. Cut the bacon into strips and fry them crisply in a pan without fat while turning. Peel apples, cut into quarters, remove core and cut flesh into fine cubes.
Add 2 tbsp. apple cubes to the bacon and sauté briefly. Cook the remaining apple cubes for the last 10 minutes with the potatoes. Peel onion and cut into strips. Remove the sausages from the pan. Stew onion and sauerkraut in the frying fat for about 5 minutes.
Season to taste with salt, pepper and sugar. Fold the sausages into the sauerkraut and keep warm. Heat milk and butter. Drain the potatoes, add the milk mixture and mash with a potato masher until mashed.
Season to taste with salt, marjoram and nutmeg. Arrange and sprinkle with apple bacon and marjoram.