Peel and quarter the apples and cut out the core. Cut apples into thick slices and boil them up in a pot with sugar, 150 ml apple juice, lemon juice and peel. Simmer covered for 4-5 minutes.
Mix 5 tablespoons of apple juice and cornstarch and stir into the compote. Let it boil again for about 1 minute. Remove lemon peel and arrange the compote in a bowl. Wash and peel the potatoes and cut them roughly into pieces.
Cook the potatoes in salted water for about 20 minutes. Peel onions, dice one finely and cut the rest into rings. Wash marjoram, dab dry and chop except for something to garnish. Knead the ground pork, egg, breadcrumbs, diced onions, marjoram, mustard and pepper in a bowl.
Shape approx. 8 meatballs with moistened hands. Heat the oil in a pan and fry the meatballs for 6-8 minutes, turning. Remove from the pan and fry the onion rings in the hot frying fat until golden brown.
Finally add 20 g butter and keep warm. Heat the milk. Drain the potatoes, add the milk and 20 g butter and mash everything to a puree. Season to taste with salt and nutmeg. Arrange the meatballs with the puree and apple compote on plates.
Spread onions with the frying fat on top and serve sprinkled with marjoram and garnished.