Put the ginger, bamboo shoots and 2 spring onions, roughly chopped, into a processor and blast until finely chopped. Add the prawns, 1 tbsp each soy sauce and rice wine, 1 level tbsp cornflour, 1 tsp salt and some pepper and blast again until roughly minced, then tip this over the pork mince and mix well. Form into uneven walnut-sized balls, cover, then chill until firmed. Hix the remaining cornflour with 3 tbsp water. Cut the aubergine into long-shaped chunks, then fry it in a pool of vegetable oil on all sides until it begins to turn gold, then shift the aubergine on to kitchen roll.
Drain off all but 1 tbsp of the oil, then fry the garlic without browning. Stir in the white parts of the spring onions, the remaining rice wine and soy sauce, the vinegar and oyster sauce, 350 ml water and the cornflour mix, and bubble up for a minute, while stirring. Arrange the dumplings, aubergine, and sauce in a small casserole pan or Chinese sandpot, crumbling in the preserved fish as you go. Bring to a bubble, then cover, and cook on a lowish heat (or in a 190°C/375°F/Gas 5 oven) for 45 minutes. Serve lavished with the shredded spring onion tops - shredded fresh root ginger will put punch in too.