To make the Dough combine the flour and salt in a mixing bowl. Add the egg and mix until the dough starts to come together. Gradually add warm water, a little at a time, kneading until a smooth and elastic dough forms. You may not need all the water. Cover the dough with a damp cloth and let it rest for about 20 minutes.

In a skillet, melt the butter over medium heat and sauté the finely chopped onion until translucent and lightly caramelized, approximately 5 minutes.

Boil the cubed potatoes in salted water until tender, about 15 minutes. Drain and mash until smooth.

Combine the mashed potatoes, sautéed onions, and crumbled farmer’s cheese. Season with salt and pepper to taste. Mix thoroughly and set aside to cool.

On a lightly floured surface, roll out the dough to about 1.5 mm (1/16-inch) thickness. Use a round cutter or glass (approximately 7.5 cm or 3 inches in diameter) to cut out circles from the dough.

Place a teaspoon of the filling in the center of each circle. Fold the dough over to form a half-moon shape and press the edges firmly to seal. You can crimp the edges with a fork for a decorative touch.

Bring a large pot of salted water to a gentle boil. Carefully add the pierogi in batches, ensuring they don’t stick together. Stir gently to prevent sticking. Once the pierogi float to the surface, cook for an additional 2-3 minutes. Remove with a slotted spoon and drain.

Optionally, sauté the cooked pierogi in melted butter until lightly golden on both sides for added flavor and texture.

Serve warm, drizzled with melted butter, a dollop of sour cream, and a sprinkle of chopped chives or green onions.