Add the soy sauce, sugar, salt, chicken powder, rice wine, spring onion and ginger to the minced pork and stir. Add 1 tablespoons of cold water into the mixture and stir in one direction till you feel the sense of elasticity. Set aside.
Dissolve sugar in the warm water, and then add the yeast. Let stand for 10 minutes, or until mixture is frothy. Sift the flour and baking powder into a mixing pan. Stir in the yeast mixture, mix well. Knead the dough until smooth and elastic. Place the dough in a greased bowl, and cover it with a wet towel. Let the dough rise in a warm place for about 1 hours, or until it has doubled in bulk.
Remove the dough from the bowl, and knead it on a lightly floured surface until it is smooth and elastic. Roll the dough into a long roll, and divide it into 12 pieces. Flatten each piece with the palm of the hand to form a thin circle. The center of the circle should be thicker than the edge. Place one portion of the pork filling in the center of each dough circle. Wrap the dough to enclose the filling. Pinch edges to form the bun. Let the buns stand for 30 minutes.
Add the cooking oil to the frying pan and heat till the oil is 180C/355F hot. Place the buns in and fry till little bubbles are seen on the skin and the skin turns yellow in color. Pour in the water and spread some sesame seeds and spring onion on top and cover and cook for another 2 minutes.