Chicken Asado Siopao/secrect to make fluffy and whiter siopao

#siopao Ingredients: filling: 600g shredded chicken meat 3/4 cup chicken stock (from boiled chicken meat) 3 tbsp brown sugar 1 onion, minced 3 cloves of garlic, minced 2 tbsp dark soy sauce 60 grams oyster sauce salt and pepper to taste 3 pcs. star anise 2 tbsp cornstarch dissolve in 1/4 cup water dough : 5 cups all purpose flour 1 1/4 cup warm water 2 tbsp powdered milk 4 tbsp sugar 3 tsp instant yeast 4 tbsp oil/ lard 2 1/2 tsp baking powder kindly watch the video for procedure. thank you!