Beat two eggs in a deep bowl. Mix them with two teaspoons of salt and water, and beat again.
Add the sifted flour to the egg mixture and knead the dough.
Place the dough in the refrigerator for an hour, wrapped in film.
For the potato filling, peel the onion and chop it finely.
Peel the potatoes and cut them into small cubes.
Place the chopped onion and potato in a deep container. Salt and pepper to taste, add melted butter. Mix the filling thoroughly.
Divide the manti dough into 20 equal parts: first cut into four parts, then each into five more parts. Roll each piece of dough into a flat cake, in the center of which put one tablespoon of filling.
Make the manti. To do this, lift the dough over the filling and pinch the opposite sides together in the middle. Then lift the edges of the dough over the filling on the remaining two sides and pinch them together.
Place the manti in a steamer and cook for 30 minutes at a high boil.
Serve the manti hot, immediately after cooking.