For the Siopao Filling

Cup of Yum
1. In a pot over medium heat, heat oil. Add onions and garlic and cook until softened. 
2. Add pork and cook, turning as needed, until lightly browned.
3. Add 2 cups of the water, soy sauce, oyster sauce, sugar, and star anise. Stir until well-dispersed. Bring to a boil, skimming scum that may float on top.
4. Lower heat, cover, and continue to cook for about 1 hour or until meat is fork-tender. Add more water in half cup increments as needed to maintain 1 1 /2 cups liquid.
5. With a slotted spoon, remove pork from the pot and let cool to touch. Using two forks, shred meat.
6. Remove about 1 cup of the braising liquid and set aside. Return shredded meat to pot and bring to a boil.
7. In a bowl, combine cornstarch and bout ¼ cup water. Stir until smooth and cornstarch is dissolved. Add half of the cornstarch slurry to the pot of meat and stir to distribute. Continue to cook for about 1 to 2 minutes or until thickened. Remove from pan and allow to cool.
8. In a saucepan over medium heat, combine the reserved 1 cup braising liquid and the remaining half of the cornstarch slurry. Bring to a boil, stirring regularly, for about 2 to 3 minutes or until thickened. This well be the siopao sauce.

For the Siopao Dough

1. In a bowl, combine milk, yeast, the 2 tablespoons sugar, and salt. Stir well until dissolved. Let stand for about 5 to 10 minutes or until the mixture is foamy.
2. In a large bowl, combine flour, the 100 grams sugar, baking powder, and vegetable oil. Mix well. Add a few drops of lime juice into the flour mixture.
3. Add yeast mixture to the flour mixture. Mix together until it forms a dough. Continue to mix and knead until the dough is smooth and no longer sticky.
4. Cover with a clean kitchen towel and allow to rise in a warm place for about 2 hours or until double in size.
5. Remove the dough from the bowl, place on a clean work surface, and form into a long log. 
6. With a knife, cut the dough into 10 equal size pieces and then form each piece into smaller balls. Cover the dough with a clean kitchen towel and allow to rise for about 30 minutes.

To assemble Siopao Buns

1. On a clean working surface, place one piece of dough, and with a rolling pin, roll out into about 4 to 5-inch diameter, making sure to get edges thinner than the center.
2. Place about a tablespoon of the meat filling in the center.
3. Gather the edges of the dough, pleat around the filling, and twist to fully secure. Place bun on a piece of parchment or wax paper. Repeat with remaining dough and filling.
4. Arrange prepared buns in a single layer on a flat baking sheet, cover with a kitchen towel, and allow to rise again for another 10 minutes.
5. In a steamer, place buns in a single layer, an inch-apart. Add about 2 tablespoons of vinegar to the steaming water (for whiter buns). 
6. Steam buns on low heat for about 15 to 20 minutes. Keep the lid on for about 3 to 5 minutes to prevent the buns from deflating.
7. Remove from steamer and serve with the asado sauce.