Add soda to kefir and beat well with a whisk, leave for a few minutes to let the bubbles go. Then add the egg, a little salt and beat. Pour the sifted flour and knead the dough. Wrap the dough in cling film or just put it in a bag and place in the refrigerator while we are preparing the filling.
To the minced meat, add onion chopped half rings, herbs, salt and pepper to taste. Mix well and pour in the milk, mix again.
Roll out the dough and put the filling in the center, wrap the edges of the dough in the center and fly them over. Roll the cake a little more with a rolling pin.
Pie the pie on a baking sheet covered with parchment with the seam down. In the center, make a small hole for steam to escape, just go with a fork. Smear the pie on top with vegetable oil and sprinkle with sesame seeds. Bake at 180 degrees 40 minutes.