Work all ingredients into a firm dough, knead well. Cover with cling film, leave to rest for 30 minutes.
In the meantime, clean the spinach leaves, finely dice the onions and sauté in the butter. Add the spinach, stew for 3 minutes, allow to cool, finely chop the spinach.
Add the curd cheese, diced gray cheese, peeled, mashed potatoes and the chives. Season with salt, pepper and nutmeg and mix well.
Roll out the dough, cut out the dough sheets with a round cutter (approx. 6 cm), place a little spinach filling in the middle. Brush the edges with water, fold one half of the dough over the filling so that crescent moons appear. Press the edges of the dough well (I do it with a fork) and let it steep in boiling salted water for about 8 minutes. Take out with a dumpling scoop.
Serve with grated cheese and lightly browned butter and green salad.