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.
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.
04 - Place 2 tablespoons of meat filling in the center of 5 pastry circles. Brush edges with beaten egg, cover with remaining pastry circles, and press edges to seal firmly. Crimp edges with a fork for decorative finish.
05 - Brush tops of pastries with remaining beaten egg to achieve golden brown finish during baking.
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.
07 - Let pastries cool slightly before serving warm.