Potato and Cheese Pierogi

Combine flour and salt, then mix in the egg and warm water to form a shaggy dough.

Knead on a floured surface for about 10 minutes until smooth. Cover and rest for 30 minutes.

Boil the potatoes until tender, drain well, and mash while still hot.

Cook the onion in butter over medium-low heat until deeply golden, about 15 minutes.

Combine the mashed potatoes with cheese and half the onions. Season to taste.

Roll the dough thin and cut circles about 8cm across.

Place filling in the center of each circle, fold in half, and press edges firmly to seal.

Boil in salted water in batches until they float, then cook 3-4 minutes more.

Serve topped with the remaining onions, sour cream, and fresh dill.