Boil the potatoes, peel them and cut them into slices while still hot. Mix the meat stock, vinegar, salt and pepper, pour over the potatoes and stir, leave to stand for 30 minutes.
Chop the eggs, cut the onion into fine rings, cut the chives into rolls (or finely chop the dill) and sprinkle everything over the potatoes. Mix the crème fraîche with the mustard and stir into the potato salad, season to taste and add salt if necessary.