Vareniki with cabbage and mushrooms

Ingredients for 8:

3 cups wheat flour
1 cup water
6 tbsp vegetable oil
1 lb cabbage
½ lb mushrooms
1 onion
Salt on taste

Method:

Clean and wash mushrooms and boil until ready (10-15 minutes), then dry and cut into small cubes.
Slice cabbage thinly into short thin stripes, fry for 15 minutes on a pre-heated skillet with 3 tbsp oil, stirring thoroughly. Cut onions into small cubes, fry with 2 tbsp oil.
Mix cabbage, onions, salt, and set aside.
Make dough with flour, water, salt, let stand for 20 minutes in a warm place.
Roll out dough thinly, shape circles from it with cup or glass.
Put 1 tsp cabbage-mushrooms mix on the center of piece of round dough, and pinch the edges of the dough. Traditionally, vareniki have a semi-circular shape.
Boil water or broth, add vareniki in it and boil for 15 minutes on low heating or until ready.
Serve with sour cream, or sprinkle with vegetable oil and salt.