For the dough: break up yeast with 50 ml of warm water, add 1 tbsp. sugar. Stir, leave in a warm place for 10-15 minutes. Separately mix 200 ml of warm drinking water with milk, add eggs, vegetable oil, the remaining sugar and salt. Stir until smooth. Add the sifted flour portion-wise, stirring intensively, knead to a thick sour cream consistency. Pour in the yeast, stir quickly, cover with a towel and leave in a warm place (about 40°C) for 1.5 hours. Add 70-100 g of sifted flour. Knead and leave for 1 hour. For the filling: Combine beef and pork. Peel onion and chop finely. Add to the meat along with salt, pepper and 100 ml of ice water. Intensively knead. Divide dough into 18-20 pieces and roll each of them into a 1cm thick flat cake. Put minced meat into the center, mold as a classic patty, connect the two ends together, twist and press down so that belyash was 1.5 cm thick. Deep fry for 7-10 minutes, pouring in hot oil at regular times.