Classic Varenyki with Onions

Method

1. 1. Peel and boil the potatoes until tender, then mash them.
2. 2. In a pan, melt the butter and sauté the onions until golden.
3. 3. Mix the mashed potatoes, sautéed onions, salt, and pepper.
4. 4. In a bowl, combine flour, egg, sour cream, and milk to make a dough.
5. 5. Knead the dough for 5 minutes, then let it rest for 20 minutes.
6. 6. Roll out the dough and cut into small circles.
7. 7. Place a spoonful of the potato mixture in the center of each circle.
8. 8. Fold the dough over and seal the edges with a fork.
9. 9. Boil the varenyki in salted water until they float, then serve with a dollop of sour cream.