Supper White Steam Meat Bun

Eleo and I like this kind of Chinese style steam meat bun very much. We like to have then for lunch with a bowl of hot soup.
The bun is very white. The secret ingredient is Soya flour. If you do not add the Soya flour, your bun will have a little yellow colour. I used to skip this, but this time I want to make a perfect bun as we have in the restaurant, so I give it a try. And it works!

(Six medium Bun)
Dough:
AP flour: 200g
Soya flour: 1.5tsp
Warm water: 130g
sugar: 1Tb
Cooking oil: 1/2Tb
Pinch of salt
Yeast:3g
Baking powder: 3g

Filling:
Shredded Chinese cabbage: 200g
Ground pork: 1/3 pound (Can be substituted by ground beef or chicken)
Ginger, green onion, sesame oil, salt & pepper

To make the dough, put all the ingredients together, knead into a smooth dough. Put into a lightly greased bowl to let it rise in a warm place for 45 minutes. In the mean time, put some salt into the shredded cabbage, leave it for 10 minutes. Discard the excess water. Then add all the ingredients of the filling together, set aside. When the dough is ready, take it out, cut into 6 pieces. Fill in the cabbage ground port filling, put on the Chinese bamboo steamer with parchment paper. Relax for 15 minutes in a warm place. Before steam the bun, make sure the water is boiling. Steam for 10-12 minutes in medium to high heat. After the bun is done. Don't open the lip at once. Leave the whole pot on the stove for 15 minutes, otherwise, the bun will shrink!