Heat the oil in a wok saucepan over low-medium flame. Cook the eggplant in batches until soft, but not coloured. Set aside.
Pour the oil out of the wok, leaving 4 tablespoons of it in the wok. Heat the wok over med-high flame.
Toss in the spring onion, ginger and garlic and stir-fry for 2-3 minutes until soft. Do not let it brown.
Add the Shaoxing wine, soy sauce, soya bean paste and ½ cup water. Mix it together and add the cooked eggplant. Reduce heat to medium, gently mix and season with sugar and vinegar. Stir through the cornflour liquid.