Place the pork, spring onions, water chestnuts, ginger purée, soy sauce and teriyaki sauce in a food processor and pulse to make a rough paste. Place spoonfuls of the mixture in the centre of each wonton wrapper and lightly brush the edges with water. Gather up the edges to make a pasty shape and pleat the edges a few times to enclose the filling.
Heat a large nonstick frying pan until hot. Add the oil and arrange the dumplings in a single layer in the pan (you may have to do this in 2 batches). Fry for 2 minutes, until golden on the bottom, then pour in the measurement water. Cover and cook for 6–7 minutes until the water has been absorbed.
Mix together the dipping sauce ingredients and serve with the dumplings.