In a large mixing bowl, combine pork, cabbage, chives, ginger, garlic, chili oil, sesame oil, Shaoxing cooking wine, soy sauce, sugar, salt and black pepper; stir until well blended. Cover with plastic wrap and transfer to the refrigerator for 1 hour.
Scoop meat mixture and place it in the center of a wonton wrapper. Wet half of the edge with water and fold over. For crimping, make a small fold, pull slightly to the side and press down firmly; repeat until reach the other end. To make it look prettier, bend it to form a crescent shape. Place gyoza on a plate lightly floured. Keep filling until meat mixture is gone.
In a non-stick skillet over medium-high heat, add canola oil. When hot, place gyoza in a circle, flat side down, and cook for 2 ½ to 3 minutes or until nicely browned. Pour in water, cover and steam for 3 minutes.
Remove from the heat and serve immediately with gyoza sauce. Makes between 30 to 35 gyoza.