Remove the pork from the oven and set aside to cool.
Chop the spring onions into small rounds.
Place the reserved marinade over a medium heat and bring to a simmer, add a pinch of pepper, the oyster sauce, hoisin sauce and chopped spring onion. Cook for 5 minutes.
Cut the meat into small pieces and add it to the simmering marinade. Cook this for a further 5 minutes until everything is sticky.
Divide the dough into 12 equal balls and then flatten a ball into the palm of your hand.
Spoon about 1 tablespoon of pork mixture into the dough and then gather and pinch it up to enclose the filling.
Place the completed bun onto a square of cooking paper.
Repeat with the remaining buns.
To cook, place the buns in a steamer allowing plenty of space for expansion.
Steam for 15-20 minutes until they feel springy.
Serve with a dipping sauce of your choice or enjoy them plain.