Ukrainian Varenyky with Potato Filling

Method

1. Boil the potatoes until tender, then mash them.
2. In a pan, sauté the onion in butter until softened.
3. Mix the mashed potatoes, sautéed onion, salt, and pepper.
4. In a separate bowl, mix the egg and flour to make the dough.
5. Roll out the dough, cut into circles, and fill with the potato mixture.
6. Cook the varenyky in boiling salted water until they float.
7. Serve with sour cream or fried onions.