To make the dough, mix together the flour, yeast, sugar, and salt. Add the oil and 200ml of lukewarm water and knead in a food processor with the dough hook for 5 minutes until it forms a smooth dough. Cover with a kitchen towel and leave to prove for 45 minutes in a warm place.
To make the filling, shell the prawns, wash the spring onion, and cut into big pieces. Peel the ginger and combine everything with the pork mince. Finely chop all ingredients. Season with soy sauce, Chinese five-spice powder, shopped coriander, and salt.
Divide the dough into portions and press or roll out flat into hand-sized pieces. Place some of the filling in the centre of each piece of dough. Wet the edge with a little water and bring together to cover the filling.
Steam in the combination oven for 30 minutes on setting 1. Sprinkle with black sesame seeds before serving with soy sauce for dipping.