Heat the oil over medium heat and fry the curry paste for 4-5 minutes until the paste begins to split, then add the sugar, cooking for another 2-3 minutes.
Stir in the chicken stock, and Coconut Milk.
Add the lime leaves and chicken and bring to the boil. Reduce to a simmer and cook covered for 20-25 minutes until the sauce is thick and the chicken is almost cooked through and tender.
Add the diced aubergine and simmer for a further 10-15 minutes until the aubergine is tender.
Season with salt, lime juice, and a splash of fish sauce to taste. Spoon into bowls and top with chillis, coriander, and Thai basil leaves.