Filled with beef, mozzarella, and cheddar, piroshkis are our new stuffed pastry obsession.
11/2 cups warm milk
1/2 tablespoon sugar
1 tablespoon dry active yeast
1/2 teaspoon salt
1 large egg
2 tablespoons olive oil
3 1/2 - 4 cups all-purpose flour
1 beaten egg, for egg wash
1 extra-large sweet onion
2 garlic cloves
1 to 11/2 pounds ground beef, 85 percent lean
1 large egg
1 cup grated mozzarella cheese
1/2 cup grated sharp cheddar cheese
2 teaspoons salt
1 teaspoon ground black pepper
1/4 cup fresh dill, chopped
Warm milk in microwave until lukewarm to touch. Pour into a large bowl and whisk in sugar and yeast. Let the mixture stand for 5 minutes. Whisk in the salt, egg, and oil until smooth. Gradually start adding flour 1 cup at a time, forming a very soft but not sticky dough.
Turn out onto well-floured work surface and knead for several minutes until smooth. Place dough in a large bowl and cover with a towel. Let dough proof until doubled in size, about 1 hour. Punch dough down and divide into 16 even pieces. Keep covered on a well-floured surface.
While dough is proofing, prepare the filling. Puree the onion and garlic in a food processor. Combine all filling ingredients in a large bowl. Use your hands to mix everything together into a uniform mixture. Cover and set aside.
Prepare piroshki. Roll out each piece of dough on a well-floured surface into a large circle. Place filling in the center, then begin pulling the dough together, starting from the top. Pinch and seal the dough over the filling, taking care not to get filling onto the edges.
Place piroshki seam-side up onto a baking sheet lined with parchment paper. Brush piroshki with egg wash. Allow them to proof for 30 minutes. Meanwhile, preheat oven to 350°F.
Bake piroshki in preheated oven until golden brown, about 25-30 minutes. Remove from oven and cool slightly before serving.