Heat the oil in a wok or frying pan over a medium heat. Add the onion and fry for 6–8 minutes until soft.
Blend the curry paste with a little of the coconut milk and add to the pan. Fry for 1 minute, then add the chicken and stir vigorously for 3 minutes. Add the remaining coconut milk, fish sauce, lime juice and agave syrup. Stir well, reduce the heat to low and simmer gently for 20 minutes.
Increase the heat to high, add the aubergines and cook for 6–8 minutes. Remove from the heat, stir in the chopped basil and serve immediately.