Pierogi

Ingredients

• 3 cups all-purpose flour
• 0.75 tsp fine salt – for dough
• 1 egg
• 0.875 cup water – warm
• 2 pounds russet potatoes – peeled and cut into chunks
• 1 tbsp kosher salt – for potato water
• 2 tbsp unsalted butter – for filling
• 1 medium onion – finely chopped (for filling)
• 10 ounces farmer cheese – crumbled
• 1 tsp fine salt – for filling
• 0.5 tsp black pepper – for filling
• 3 tbsp unsalted butter – for topping
• 1 large onion – thinly sliced (for topping)
• 1 tbsp kosher salt – for pierogi boiling water
• sour cream – for serving

Instructions

1. Make the dough: In a large bowl, whisk together the all-purpose flour and fine salt (for dough). Beat the egg with the warm water, then pour into the flour. Stir with a fork until a shaggy dough forms, then knead on the counter until smooth and elastic, 8–10 minutes. Cover and let rest at room temperature for 30 minutes.
2. Cook potatoes for the filling: Put the russet potatoes in a pot, cover with cold water by about 1 inch, and add the kosher salt (for potato water). Bring to a boil, then simmer until the potatoes are very tender, 12–15 minutes. Drain well and return to the hot pot to steam off excess moisture, 2–3 minutes.
3. Prepare the onion for the filling: While the potatoes cook, melt the unsalted butter (for filling) in a skillet over medium heat. Add the onion (for filling) and cook, stirring, until soft and lightly golden, 8–10 minutes. Remove from heat.
4. Mix the filling: Mash the hot potatoes until smooth. Stir in the farmer cheese, the sautéed onion (with any butter), fine salt (for filling), and black pepper (for filling). Taste and adjust seasoning. Let the filling cool to room temperature.
5. Roll the dough: Cut the rested dough in half; keep one half covered. Roll the first half to 1/16–1/8 inch thickness. Cut 3-inch rounds with a cutter or glass. Gather scraps to reroll once.
6. Fill and shape: Place about 1 tablespoon of filling in the center of each round. Fold into a half-moon, pressing out air, and pinch the edges firmly to seal; crimp with fingers for extra security. Set shaped pierogi on a lightly floured towel or sheet.
7. Boil: Bring a large pot of water to a rolling boil and add the kosher salt (for pierogi boiling water). Drop in pierogi in batches without crowding. Cook 3–5 minutes, until they float and the edges are tender. Lift out with a slotted spoon and drain.
8. Make the onion topping and finish: In a large skillet, melt the unsalted butter (for topping) over medium heat. Add the onion (for topping) and cook, stirring often, until deep golden and sweet, 10–12 minutes. Add drained pierogi to the skillet and pan-fry until lightly crisp at the edges, 2–4 minutes per side.
9. Serve: Transfer to plates, spoon the onion-butter over top, and serve hot with sour cream (for serving).