In a large mixing bowl, combine pork, prawns, Chinese chives, spring onions, light soy sauce, sugar, salt, white pepper, sesame oil, corn flour, chicken powder and oil. Mix well and set aside.
Take a gyoza wrapper and add 1tsp filling to it.
Wet the edges of the wrapper with water. Fold and seal. Pleat the folded edge. Place them on a plate. Do the same to make 20-30 dumplings.
Cook them in a pot of boiling water until they start floating.
Add one cup cold water on top of the boiling dumplings. Bring it to boil again. Repeat this 3 times.
For the dipping sauce, take a small bowl and mix Light Soy Sauce, Chinkiang Chinese Vinegar, Sesame Oil, Fresh Ginger, and Spring Onion. Set it aside.
Drain the dumplings in a large bowl after 10 minutes of boiling.
Serve the dumplings hot with the dipping sauce.