Thinly slice the aubergines and place in a bowl with the curry powder. Season with salt and toss to mix well.
Fill a wok or small, deep saucepan one-quarter full with sunflower oil and heat to 180°C–190°C (350°F–375°F), or until a cube of bread browns in 30 seconds. Deep-fry the aubergines, in 2 or 3 batches, for 1–2 minutes or until crisp and golden. Drain on kitchen paper.
Transfer the aubergines to a large serving plate, scatter over a small handful of chopped mint and serve immediately with lemon wedges and a sprinkling of chilli powder and sea salt.