"A meat-filled dumpling similar to a ravioli that is popular throughout Russia. Serve with sour cream or yellow mustard or vinegar (sour cream recommended). Place the extra pelmeni you have just made that are still on your baking sheet in the freezer until frozen and move to a plastic bag so you'll have pelmeni goodness available for the next few days."
Stir flour and 1 teaspoon salt together in a bowl.
Stir eggs and 2/3 cup water together in a separate bowl. Pour into the flour mixture; mix until dough is combined. Turn dough out onto a floured work surface; knead until smooth, about 6 minutes. Place dough in a plastic bag.
Combine pork, beef, water, and onion in a separate bowl; season filling with salt and pepper.
Turn dough back onto the work surface. Roll and divide into long snakes about 3/4-inch thick. Cut into 3/4-inch-wide segments; flatten into 2-inch circles using a rolling pin.
Place a 1-inch-wide scoop of the filling on each dough circle. Fold dough over filling; pinch edges shut. Pinch the 2 opposing corners together behind the flat edge. Place pelmeni on a floured baking sheet.
Bring a saucepan of salted water to a boil. Add about 15 pelmeni; cook until they float to the top, 5 to 7 minutes.