1. To make the unleavened dough, mix together flour, water, egg and 1/2 teaspoon salt.
2. To make the filling, in a medium bowl, mix together ground beef, 1 teaspoon salt, garlic powder, black pepper and finely chopped onion.
3. Roll out the dough to about 1/8 inch thick.
4. With the help of a glass, cup or biscuit cutter cut out about 1 1/2 inch rounds.
5. Put a scant teaspoon of the filling on the each round.
6. Fold over and seal the edges with your fingers or a fork, then bring the ends round and pinch them together.
7. You should get about 50 pelmeni. Leave the amount you want to cook now and put the rest to the freezer (they can be kept in a freezer for up to 3 months).
8. Bring 3 quarts of water to boil in a medium pot. Add 1 1/2 teaspoon salt. Drop in the pelmeni and simmer uncovered for about 10-15 minutes (they should rise to the surface).
9. Remove the pelmeni from the water, drain a bit, put the desired amount on a plate, top with a tablespoon of sour cream and serve.