Mix in the bowl of a food processor the flour, salt, and baking powder.
1½ cups flour, ¼ teaspoon baking powder, ¼ teaspoon salt
Add the butter and pulse several times until you've got coarse crumbs. (If you don't have a food processor then put all the ingredients in a large bowl and cut with two knives the butter in small pieces until you have a coarse grain.
1 stick butter
Add the egg and sour cream and pulse 3 times.
1 egg yolk, 5 tablespoons sour cream
Put the dough onto a lightly floured work surface and knead a bit.
Form a disk and wrap it in plastic wrap. Refrigerate for at least 1 hour.
Heat the oil in a frying pan.
1 tablespoon oil
Add the onions and stir-fry for 3 minutes, until translucent.
Add the beef and fry it lose. Put the onion, beef, eggs, beef broth, flour, sour cream, dill, parsley, salt, and pepper in a bowl and mix well.