Make the pork aspic

• Warm the chicken stock slightly and stir in the gelatine until dissolved.
• Pour into a shallow dish and chill until set into a firm jelly.

Mix the filling

• Combine the pork mince, soy sauce, oyster sauce, Shaoxing wine, sesame oil, sugar, white pepper, ginger and half the spring onions.
• Stir in the cold stock in a few additions until the mixture is sticky and glossy.
• Finely dice the set aspic and fold it through the meat, then chill the filling.

Knead the dough

• Mix the flour, yeast, sugar, salt and baking powder, then add the warm water.
• Knead into a smooth, soft dough.
• Cover and let it rise until doubled.

Shape the buns

• Divide the dough into small pieces and roll each into a thin round.
• Place a spoonful of filling in the centre and pleat the edges to seal.
• Set the buns pleat-side down and rest them briefly.

Pan-fry the buns

• Heat the oil in a frying pan and arrange the buns snugly, pleat-side down.
• Fry until the bases are golden, then add water, cover and steam until the buns are fluffy and cooked through.
• Uncover and let the water evaporate so the bottoms turn crisp.

Finish and serve

• Scatter the sesame seeds and remaining spring onions over the buns.
• Serve immediately while the bottoms are still crispy.