Stir the contents of the bag into 650 ml lukewarm water. Bring to the boil while stirring and cook at low heat with slightly opened lid for about 20 minutes. In the meantime, peel and finely dice the shallot for the dumplings. Knead the ground pork, minced beef, quark, breadcrumbs, shallot, marjoram, a little salt, pepper and mustard. Form small dumplings with moistened hands. Clean and wash spring onions and cut into fine rings.
Quarter the apple, cut out the core and cut the quarters into thin slices. Heat oil in a pan and fry the meatballs in it all around. Add the apple slices and spring onions, fry for 1-2 minutes and deglaze with apple juice. Bring to the boil, add to the finished potato soup and cook again for about 1 minute. Season to taste with salt and pepper and serve sprinkled with fresh marjoram leaves as desired