Traditional Polish Pierogi with Sour Cream and Onions

Method

1. In a large bowl, mix flour and salt. Gradually add water, kneading until smooth. Cover and let rest for 30 minutes.
2. In a separate bowl, combine mashed potatoes, cheese, and a pinch of pepper. Mix well.
3. Roll out the dough and cut into circles. Place a spoonful of filling in the center of each circle.
4. Fold the dough over the filling, pressing the edges to seal. Pinch the edges to form a crescent shape.
5. In a large pot, bring salted water to a boil. Add the pierogi and cook until they float to the surface, about 3-4 minutes.
6. While the pierogi cook, melt butter and oil in a skillet. Add onions and sauté until golden brown.
7. Drain the pierogi and toss with the caramelized onions. Serve with a dollop of sour cream on top.