Combine all filling ingredients in a large bowl. Mix with a chopstick in one direction for 2 minutes — the filling will become smooth and sticky. This is the texture you want.
Fold dumplings
Lay a wonton wrapper on a clean dry surface. Place 1 tsp filling in the centre. Wet the edge with a finger dipped in water.
Fold in half, pinching the centre top first, then pleating each side toward the centre (3-4 pleats per side). Press to seal.
Place on a tray dusted with cornflour. Repeat. (You can freeze at this stage on the tray; once solid, bag.)
Cook (potsticker style)
Heat 2 tbsp oil in a large non-stick pan over medium-high. Place dumplings flat-side-down in the pan in a single layer. Cook 2 minutes until the bottoms are golden.
Pour 80mL water into the pan. Cover. Steam 6 minutes.
Uncover. Cook 2 more minutes until the water has evaporated and the bottoms re-crisp.
Serve with black vinegar, soy sauce, chilli oil, and sliced ginger and shallots.