Heat 1 tablespoon of oil in a frying pan. Halve the sausage and fry it for about 6 minutes, turning it over. Peel and halve onions and cut into strips. Remove the sausage from the pan. Sauté onions in frying fat.
Add the sauerkraut and braise for about 10 minutes while turning. Season to taste with salt, pepper and sugar. Heat 2 tablespoons of oil in a second pan and fry the gnocchi for about 5 minutes, turning them over.
Season to taste with salt and nutmeg. Add the sausage to the sauerkraut and warm up briefly. Arrange everything on plates.