Heat the coconut oil over a medium/high heat in a non-stick wok and add the curry paste until the paste has dried up and the oil is separating.
Add the chicken and aubergines to the pan and fry for about 4 minutes until the chicken turns from raw to whitish in colour. Add a little coconut milk to keep the paste smooth.
Add the rest of the coconut milk and stock, bring to a boil and reduce the heat to low so everything simmers gently. Add the sugar but save a little bit to adjust the seasoning before serving. You can add some water if you like your curry more on the soupy side. Stir in the fish sauce and cook for 4. Add the tomatoes and beans and cook for another 5 minutes. Turn off the heat and stir in the Thai basil. Adjust the seasoning with sugar and fish sauce.
Serve in bowls next to Jasmine rice.