Add milk, and bring the dough together. The dough should be sticky, but manageable – if needed, add more flour or a little water.
Knead for about 3 minutes. Rest at room temperature for 15 minutes.
Roll each piece into golf ball size on a lightly floured surface.
Flatten balls in the palm of your hand, roll into discs and fold over.
Place on a piece of baking paper, and pop into a steamer.
Steam buns for 12-15 minutes, or until cooked through.
Mix all ingredients together and pour over beef.
Cover and roast in a preheated oven at 160°C for about 3 hours.
Serve beef sliced in buns with shredded spring onion, coriander and chilli.