For the dough, mix the flour with baking soda, baking powder and salt. Very cold oil RUB on a coarse grater directly into the flour mixture, stir to get crumbs. Add cold sour cream, knead the dough. Wrap it in film and refrigerate for 30-50 minutes.
Preheat the oven to 180 °C. for the filling, clean the onion and cut into quarters of the rings. Fry in oil over medium heat until Golden brown, 15 minutes. Sprinkle with paprika, stir and remove from heat.
Lightly beat the eggs, mix with melted cheese and fried onions and paprika.
Divide the dough into 2/3 and 1/3. Roll out the most and put in shape with a diameter of 24 cm, the edges a little hung. Put the cheese and onion filling on the dough.
Roll out the remaining dough, cover the filling. Wrap the hanging edges of the dough on the filling and connect the edges of the two dough cakes. Carefully pinch the edges. In the center of the pie, make a hole for steam. Grease the dough with yolk mixed with 1 tsp water.
Put in the lower third of the oven and bake until Golden brown, 40-50 minutes. This pie tastes best warm.