Prepare egg, water, flour and oil into a smooth dough. Knead together heartily with nutmeg, salt and pepper, cover with cling film and rest preferably for one night.
Heat clarified butter in a frying pan, sauté onions until translucent and cool. Make well washed potatoes in salted water with caraway seeds so that they pierce easily with a fork. Drain potatoes, steam, peel and cut into slices.
Mix minced meat with egg yolk, chive rolls and onions and season with salt and pepper. Roll out the dough very thinly and cut into rectangles. Form small heaps of the mince mixture on the lower third of the rectangle, brush all around with egg white and beat together, perhaps flattening with a fork on three sides. Cook the Maultaschen (depending on their size) in hot meat or vegetable soup for four to six minutes.
Sauté the onions in a little bit of oil, add the bacon, pour in a little bit of beef broth and let it cook. Add vinegar, remaining oil and the rest of the clear soup and bring to a boil. Put the potato slices in a large enough bowl, pour the hot vinegar-oil marinade over them, mix well and season with salt and freshly ground pepper. Let the finished potato salad sit for twelve to 15 minutes.
Serve:
Arrange potato salad on plates, remove Maultaschen from hot clear soup and add.