Mix the flour, eggs, salt and water and knead well. Let rest a little.
Boil the potatoes and fry the onions in a little butter in the pan. Then mash the potatoes, add the herbal cream cheese and the onions and mix everything well, this is best done with a hand mixer.
Roll out the dough thinly and cut out circles around the size of a saucer. Fill the dough circles with the potato and cheese cream (1-2 tablespoons). Brush the edges with egg yolk, fold one side over so that it looks like a crescent and press the edges firmly on. Cook in a large saucepan with salted boiling water for 15-20 minutes.