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 ingredients are well incorporated and the mixture becomes sticky.
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 the edges with beaten egg, then cover with remaining pastry circles. Press edges firmly to seal and crimp with a fork for a decorative finish.
05 - Brush the tops of each pastry with remaining beaten egg to achieve a golden, glossy finish when baked.
06 - Arrange pastries on the prepared baking tray, leaving space between each for expansion. Bake for 20-25 minutes until puffed and golden brown.
07 - Remove from oven and let cool for 5 minutes before serving warm.