Classic Polish Pierogi with Mushroom and Sauerkraut Filling

In a mixing bowl, combine the flour and salt. Make a well in the center and add the egg and water. Mix until a dough forms.

Knead the dough on a floured surface for about 5-7 minutes, until smooth. Cover with a cloth and let it rest for 30 minutes.

In a pan, melt the butter and sauté the chopped onion until translucent. Add the chopped mushrooms and cook until soft and the moisture has evaporated.

Stir in the sauerkraut and cook for an additional 5 minutes. Allow the filling to cool before using.

Roll out the dough to about 2 mm thick. Cut out circles using a round cutter or glass.

Place a teaspoon of the filling on each dough circle and fold it over to form a half-moon shape. Press the edges tightly to seal.

Bring a large pot of salted water to a boil. Cook the pierogi in batches for about 5 minutes or until they float to the top.

Remove the pierogi with a slotted spoon and optionally pan-fry them in a little butter until golden brown.

Serve hot, garnished with sour cream, fresh dill, and a sprinkle of black pepper.