Prepare ingredients for a yeast-free meat and potato pie. Melt the butter. Cut the beef into small pieces. Peel the potatoes and chop them too. Remove the skin from the onion and finely chop it. Tip: Before cutting, the beef should be frozen a little to speed up the process.
Prepare the dough. Mix butter and sour cream in a bowl. Add egg, baking powder and salt. Add flour. Knead the dough. Divide it into two parts, making one slightly smaller than the other. Cover with a towel.
Prepare the filling. Mix onions, potatoes and beef, add salt, cumin and pepper.
Bake the pie. Roll both parts of the dough into thin oval cakes. Place a large flatbread on a baking sheet lined with foil. Spread the filling on top, leaving a couple of centimeters from the edge. Cover with the second part of the dough, press the edges. Beat the egg with water and brush the top of the pie. Make several cuts on the pie with a knife. Bake at 180 degrees for 20-25 minutes.
Cut the finished yeast-free meat and potato pie into rectangular slices and serve.