Vegetarian Pierogi with Mushrooms

Method

1. In a bowl, mix flour, egg, water, and salt to form a dough. Knead until smooth, then let rest for 30 minutes.
2. Sauté mushrooms and onions in butter, add minced garlic, and let cool.
3. Roll out the dough, cut into circles, fill with mushroom mixture, and fold into half-moons.
4. Boil the pierogi in salted water until they float, then drain.
5. Toss with garlic butter sauce and serve with sour cream.