Siopao Bola-bola + Sauce Easy Whiter Dough#siopao

Ingredients for dough: 4 cups all purpose flour 2 cups warm milk 3/4 tbsp quick rise yeast 1/4 cup sugar 3 tbsp vegetable shortening 1 1/2 tbsp baking powder for filling: 300g ground pork salt and pepper 1 tbsp soy sauce 1 egg 1 tbsp cornstarch 2 tbsp onion 1 tbsp garlic 1/4 cup carrot 1/4 cup spring onion sliced boiled eggs for sauce 2 cups water 1/4 cup soy sauce salt and pepper chili powder ( optional ) 2 tbsp brown sugar 1/2 tsp onion powder 1/2 tsp garlic powder 1/4 cup pineapple juice 1 tbsp vinegar 1/2 tbsp oyster sauce 1 1/2 tbsp cornstarch 1/4 cup water