Boil up the milk. Cut pretzel into small cubes. Pour hot milk over the pretzel and let it stand for about 30 minutes
Peel and finely chop the onion. Heat 1 tsp. oil in a frying pan. Sauté diced onion for 2-3 minutes and add to the rolls. Wash parsley, shake dry and put 1 stalk aside. Finely chop the leaves of the remaining stems. Puree eggs and parsley. Add the egg mix to the dumpling mixture and mix well. Season with salt, pepper and nutmeg
Spread the dumpling mixture on the long side of a damp tea towel (approx. 7 cm Ø; 18-20 cm long). Roll up the mass firmly and tie the ends together with kitchen string. Let the dumplings simmer in boiling salted water for about 50 minutes, turning regularly
Whip the crème fraîche until thick and creamy. Stir in mustard, season with salt and pepper. Chill the mustard cream. Peel and halve the red onions and cut into thin strips. Heat 1 tablespoon of oil in a frying pan. Sauté the onions and aniseed for about 3 minutes, then sprinkle sugar over it. Let the sugar caramelize, deglaze with vinegar and 2 tbsp. water. Cover the onions and cook while stirring occasionally. Season with salt and pepper
Take the dumpling roll out of the water bath, let it cool down a little and remove it from the tea towel. Cut dumplings into 16 slices. Heat 2 tablespoons of oil in a frying pan and fry the dumpling slices for about 3 minutes while turning them, remove and keep warm.
Cut the meatloaf first crosswise, then horizontally in half. Heat 1 tablespoon of oil in a frying pan. Fry the portions of Leberkäse for 2-3 minutes, turning them over until golden brown. Remove. Cut parsley leaves into strips. Stack 2 dumpling slices, 2 slices of meat loaf, onions and 1 tbsp. mustard cream each to form burgers, sprinkle with parsley and serve immediately. Serve with the rest of the mustard cream
Waiting time approx. 30 minutes