Cut the aubergines in half lengthways and place on a heatproof plate. Place a trivet or steamer rack in a wok and pour in about 5 cm (2 inches) of water. Bring the water to the boil and lower the aubergine plate on to the trivet or rack.
Reduce the heat, cover and steam for 25–30 minutes (replenishing the water in the wok if needed) until the aubergines are cooked through and soft to the touch. Remove the aubergines from the wok, transfer to a serving platter and allow to cool.
Meanwhile, heat the oil in a nonstick frying pan. Add the garlic, ginger, spring onions and chillies and stir-fry for 2–3 minutes. Remove from the heat and stir in the soy sauce, rice wine and sugar.
Toss the mint leaves, coriander and water chestnuts with the aubergines and pour the garlic and ginger mixture evenly over the top. Sprinkle over the peanuts, toss gently and serve immediately with lime wedges and steamed egg noodles or rice, if liked.