Pour water over the sifted flour and add salt. Mix the dough first with a fork and then with your hands. Sprinkle the table with flour and transfer the dough. Knead the dough until smooth.
Form the dough into a ball and place it in a bowl. Cover with cling film and refrigerate for an hour.
For the filling, mix the minced meat with onions, potatoes and cabbage. Add the tomato sauce and mix well.
Form a sausage from the dough and divide it into equal parts. Roll out the dough thinly (about 2 mm thick). Put a tablespoon of filling in the middle of each flatbread. Make manti.
Cook the manti in boiling water for about 10 minutes.