1. Sauté onion in butter over low heat until onion is translucent.
2. Add mushrooms, sour cream, salt, and pepper
3. Sprinkle with two tablespoons flour and cook one to two minutes.
4. Place 1/4 to 1/2 teaspoon filling in each round. Fold over and seal by pressing edges with fork tines.
5. Bake on ungreased cookie sheet at 350° for approximately 15 minutes.