Chinese pork steamed bun recipe

{ Ingredients for dough # 1 } 8 cup Chinese all purpos flour 3 cup of water 2 tbsp of sugar 2 tpsb of instant dry yeast { Ingredients for dough # 2 } 5 cup Chinese all purpos flour 1 cup of sugar 2 cup of milk 1 tbsp of baking powder { Ingredients for stuffing inside } 2 and 1/2 of ground pork 1 bag chinese sausage style 15 of boil egg 80g mushroom 80g yellow onion 80g green onion 15g ginger 5g garlic 3 tbsp cornstar 1 tbsp of salt 2 tbsp of chicken favorite 1 tbsp of sugar 2 tbsp of vegetable oil 2 tbsp of saseme oil 2 tpsb of soy sauce 2 tbsp of oyster sauce 5g of black pepper