Boiled Gyoza Dumplings With Slippery Smooth Homemade Skins

Name: Boiled Gyoza Dumplings With Slippery Smooth Homemade Skins
Ingredients: 300 grams Ground pork; 350 grams Cabbage (finely chopped); 2 stalks Japanese leek (finely chopped); 2 clove Garlic (finely chopped); 1 piece Ginger (finely chopped); 120 ml Chicken stock; 3 tbsp Oyster sauce; 3 tbsp Sake (or preferably Shaoxing wine); 1 tbsp Soy sauce; 1 tsp Salt; 2 tbsp Sesame oil; 1 tsp Red chili pepper powder; 1 dash Pepper; 200 grams Bread (strong) flour; 250 grams Cake flour; 250 ml Boiling water; 1 Cake flour (to dust the work surface); 30 ml Soy sauce; 60 ml Vinegar; 10 ml Sesame oil; 1 Ra-yu