Put the egg and water in a bowl and stir with a whisk. Gradually add the flour until you can knead it. When the dough no longer sticks to your hands, you can roll it out thinly and cut out 5 cm circles.
For the filling:
Chop the onion and sauté in oil or butter. Cut the salmon fillets very small. Put both in a bowl, mix with the cream cheese and season with salt and pepper.
Place the filling in the middle of the circles, fold them into pockets and press the edges into place.
Then place the pelmeni in boiling water and wait for them to swim to the surface.
Now the pelmeni are ready and can be served with sour cream.