01 - Combine ground pork, onion, garlic, soy sauce, oyster sauce, sugar, black pepper, salt, cornstarch, and sesame oil in a mixing bowl. Mix thoroughly until all seasonings are evenly distributed throughout the pork.
02 - Preheat oven to 400°F. Line a baking tray with parchment paper and set aside.
03 - On a lightly floured surface, roll out puff pastry sheets to approximately 1/8 inch thickness. Cut into 10 circles using a 3.5-inch round cutter or pastry cutter.
04 - Place 2 tablespoons of meat filling in the center of 5 pastry circles. Brush edges with beaten egg, then cover with remaining pastry circles. Press edges firmly to seal and crimp with a fork for decoration.
05 - Brush tops of assembled pastries with remaining beaten egg to achieve a golden finish when baked.
06 - Arrange pastries on prepared baking tray, leaving space between each for expansion. Bake for 20 to 25 minutes until pastries are puffed and golden brown. Let cool slightly before serving warm.