Sift the flour and salt into a large mixing bowl. Add the eggs and mix until incorporated. Add water.
Using a stand mixer, mix the dough until smooth. Sprinkle flour onto a flat work surface.
In a large bowl, mix the ground meat, grated onion, salt, and pepper with your hands until well-combined.
Assemble the Pelmeni (Mold or By Hand)
To save time, use a pelmeni mold to shape the dumplings. To do so, roll out a flat piece of dough and place it on the well-floured mold. Fill each hole with meat.
Make another flat, round piece of dough and place it on top. Sprinkle with flour and use a rolling pin to roll over the dough until each dumpling is separated.
Flip the mold over and shake out the pelmeni. Dust them with flour. At this point, you can either freeze them for later or boil them to eat immediately.
Alternatively, you can make the pelmeni by hand. To do so, roll the dough out and cut small circles out of it using a cookie cutter. Place the meat mixture in the middle and fold over the sides into a half-moon shape, pinching the edges together to secure the filling inside. Connect the two corners together. Repeat until you have no dough or meat mixture left.
Boil the Pelmeni
Bring a large pot of salted water to boil. Add the pelmeni in. Once they float to the top, they are finished and ready to be taken out. Strain the pelmeni with a colander. Drizzle them with butter and serve with a side of sour cream. Enjoy!