Wash the potatoes and cook in boiling water for 20 minutes. In the meantime peel and chop the onions. Cut the bacon into fine cubes as well. Heat the oil in a pot, add the bacon and fry the onions briefly. Add sauerkraut and braise well. Deglaze with stock and apple juice, add bay leaf and juniper berries and season with salt and pepper. Cover and braise for 30 minutes.
Drain potatoes, rinse with cold water and peel. Press the potatoes through a potato ricer. Add flour, cornstarch, egg yolk, salt, pepper and nutmeg and knead briefly. Form finger-thick potato noodles with floured hands and let them simmer in portions in lightly boiling salt water. When the potato noodles float on top, remove them with a skimmer and let them drain well. Heat the fat in a pan and fry the potato noodles until golden brown, turning them over. Arrange on plates together with sauerkraut and serve garnished with parsley