Classic Polish Potato and Cheese Pierogi with Sour Cream and Crispy Onions

To make the dough, combine 2 cups all-purpose flour and 1/2 teaspoon salt in a large bowl. In a separate bowl, whisk together 1/2 cup warm water and 1 large egg. Gradually add the wet ingredients to the dry, mixing until a shaggy dough forms. Knead on a lightly floured surface for 5-7 minutes until smooth and elastic. Cover and let rest for 30 minutes.

For the filling, boil 2 medium peeled and diced potatoes in salted water for 15-20 minutes until very tender. Drain well and mash thoroughly. Stir in 1 cup farmer's cheese and 1/4 teaspoon black pepper. Taste and adjust seasoning as needed.

While the dough rests and potatoes cook, prepare the fried onions. Melt 2 tablespoons butter in a large skillet over medium heat. Add 1 large thinly sliced onion and cook, stirring occasionally, for 10-15 minutes until deeply golden brown and caramelized.

Divide the rested dough into two portions. On a lightly floured surface, roll out one portion to about 1/8-inch thickness. Use a 2.5-inch round cookie cutter or glass rim to cut out circles. Place about 1 teaspoon of potato and cheese filling in the center of each circle.

Fold the dough over the filling to create a half-moon shape. Pinch the edges firmly to seal, ensuring no filling escapes. Repeat with the remaining dough and filling.

Bring a large pot of salted water to a rolling boil. Carefully drop the pierogi into the boiling water, cooking in batches to avoid overcrowding. Cook for 3-5 minutes after they float to the surface, until tender. Remove with a slotted spoon.

Serve the hot pierogi immediately, topped with a generous dollop of 1/2 cup sour cream and the crispy fried onions.