Step 2

For the potato filling: melt 3 tbsp butter and cook the onion until translucent, about 5 minutes. Stir into the mashed potatoes and season with salt and white pepper.

Step 3

For the dough: beat together the eggs and sour cream until smooth. Sift together the flour, salt, and baking powder, then stir into the sour cream mixture until a dough forms. Knead on a lightly floured surface until firm and smooth.

Step 4

Divide the dough in half. Roll one half to 3mm (⅛ inch) thickness and cut into 7.5cm (3-inch) rounds with a biscuit cutter.

Step 5

Place a small spoonful of mashed potato filling in the centre of each round. Moisten the edges with water, fold over, and press the edges together firmly with a fork to seal. Repeat with the remaining dough using the sauerkraut filling.

Step 6

Bring a large pot of lightly salted water to a boil. Cook the pierogi in batches for 3–5 minutes until they float to the top. Remove with a slotted spoon and serve.