Knead all ingredients with the dough hook to a smooth dough, wrap it in cling film and let it rest for 30 minutes at room temperature.

Boil the potatoes with their skin in salted water until cooked in cold water, peel and grate finely in a bowl. Peel the onion and dice it. Cut the cheese into very small cubes. Sweat the onion in the 20 ml oil until translucent, then add the oil to the grated potatoes, mix with them, season with salt, pepper and divide the mixture. Fry the bacon cubes without additional fat, add the fat that has escaped to half of the potato mixture and fold in. Mix the other half of the potato mixture with the small cheese cubes and have both ready.

Peel the onions and cut into rings. Put 2 tablespoons of clarified butter in a large pan and have everything ready.

Divide the dough into 4 portions. Roll out each about 2.5 - 3 mm thin and cut out circles with a diameter of 10 cm. If you have a press (as shown here), you can do it with the help of its underside. Otherwise, use a large cookie cutter for it. Then place about 2 teaspoons of the filling on one half of the round plates, moisten the edge all around with a little water, fold the unfilled side over the filling and press the edge down. Without a press, do this with a fork. Then repeat these steps until the batter and fillings are used up.

Next, heat the 2 tablespoons of clarified butter in the pan, fry the onions for 1 - 2 minutes. When they start to turn glassy, ​​turn the temperature down halfway and then cook them slowly, turning several times, and let them brown lightly. This can take 8-10 minutes.

While the onions are cooking, bring plenty of well-salted water to the boil in two large pots. (2 pots so that you don't get confused with the fillings later when serving.) When it boils, add the pierogi, bring the water to the boil again, then turn the heat down halfway and let it simmer gently for 5 minutes. When they have risen to the surface, try one and test the texture of the dough. But the 5 minutes should be enough.

Heat the remaining 2 tablespoons of clarified butter in another, larger pan. Lift the finished pierogi (if possible separately) out of the water, let them drain well, turn them in the hot clarified butter and serve approx. 2 pieces of both types immediately together with the melted onions.

There was also a cucumber salad with slightly sweet, sour cream. But it also goes well with any kind of lettuce. The preparation for this is not included in the calculation.

You can count on 4 - 5 pierogi per person as a main course and 2 as a starter. The above number of people therefore refers to one main course.