Peel and chop the onion. Wash and dry the Kasseler. Heat the fat in a casserole dish. Brown the onions in it. Fry the smoked pork on all sides. Add sauerkraut and apple juice.
Season with bay leaves, juniper berries, salt, pepper and sugar. Cover and stew for 35 minutes. In the meantime, cut the bacon into cubes and drain in a pan without fat. Wash thyme and parsley, dab dry and chop finely.
Boil 1/2 litre of water. Remove the pot from the heat. Stir in pea puree flakes with a whisk. Put the puree in a bowl. Sprinkle with bacon and parsley. Cut the smoked pork loin into slices.
Arrange on the sauerkraut. Garnish with thyme. Serve with the purée.