Sift flour, yeast, and salt into a bowl, create a well in the center.

If using fresh yeast, mix with warm milk and a pinch of sugar, let it sit for 10 minutes until frothy.

Scald milk and butter, let cool to blood temperature.

Mix sour cream, whole eggs, and egg yolks thoroughly, add to the well along with the lukewarm milk.

Gradually incorporate the liquids into the flour mixture with a wooden spoon.

Knead vigorously for 10 minutes until the dough is elastic.

Place dough in a greased bowl, cover, and let rise to double the volume (about 1.5 hours).

Punch down the risen dough and knead briefly.

Divide the dough into two equal halves, wrap, and refrigerate until ready to assemble.

Cook salmon fillet in butter for 2 minutes on each side in a large frying pan.

Set aside the cooked salmon, season, and sprinkle with half the lemon juice. Chill until ready to use.

Cook diced onions in the remaining butter until translucent.

Add sliced mushrooms and a pinch of salt, cover, and cook until the juices run.

Remove the lid, turn up the heat, and quickly evaporate the juices from the onion-mushroom mixture.

Place the onion and mushroom mixture into a mixing bowl along with the remaining lemon juice.

Toss the onion-mushroom mixture to coat everything, then add cooked rice, raw egg, herbs, spices, and seasonings.

Mix everything well in the bowl.

On a floured board, roll out one dough half to an oblong 1/3 inch thick that fits your baking sheet.

Place the rolled-out dough on a baking sheet and spoon the rice mixture onto it, leaving a 1 1/2 inch rim.

Arrange the salmon on top of the rice and slices of hard-boiled egg on top of the salmon.

Cover with the remaining rice mixture.

Dampen the edges of the dough with water.

Roll out the second piece of dough to the same size as the first and place it over the filling.

Press together the edges firmly, turn them up, and press them together again using the tines of a fork.

Make a small steam hole in the top center of the pie.

Decorate the pie with extra dough if desired, such as leaves and braids.

Brush the pie all over with sour cream.

Bake in a preheated oven at 400F for 45-60 minutes, until the pastry is golden brown.

Place the pie on a serving platter and pour the melted butter into the hole on top. Serve hot.