Prepare yeast dough on the basis of the sour starter following the instructions to the basic recipe (see the recipe).

Fry onion in oil. Boil heart and lung, then grind and fry in oil, adjust seasonings to taste. Cut hard boiled eggs into circles.

Roll 2/3 of the dough out and transfer to a greased baking try. Put the onion, then scatter over liver and eggs. Cover with the remaining rolled out dough and tweak the edges. Let the pie sit for 30 minutes, then brush with whisked egg and bake in the oven for 1 hour.