Classic Polish Pierogi with Sour Cream and Onions

Method

1. Boil potatoes until tender, then mash them.
2. In a bowl, mix mashed potatoes with flour, egg, milk, and a pinch of salt.
3. Knead the dough until smooth, then roll out and cut into circles.
4. Fill each circle with a spoonful of mashed potatoes and fold into a half-moon shape.
5. Boil pierogi in salted water until they float to the surface.
6. In a pan, sauté onions in butter until golden brown.
7. Serve pierogi with a side of sour cream and sautéed onions.