In a large skillet, cook ground round, onions, and garlic over medium-high heat,
stirring often to break up lumps of meat, until beef has lost its pink color, about
5 minutes. Drain off excess fat. Off heat, stir in hard-boiled egg, sour cream,
dill, salt and pepper; let filling cool completely.
Heat oven to 400 degrees F.
One can at a time, separate biscuits. On a lightly floured surface roll out each
biscuit to a 3 1/2 -inch circle. Place about 1 tablespoon filling in the center
of each circle. Fold in half to enclose filling. Press edges with a fork to seal
closed. Place on ungreased baking sheet. Brush tops with beaten egg.
Bake piroshki for 15 to 20 minutes, until golden brown. Keep unbaked piroshki
batches covered with clean kitchen towels.
Serve warm or at room temperature.
Baked piroshki can be frozen and kept for up to one month. Thaw and bake