For the paste, toast the cumin and coriander seeds in a dry frying pan over a medium heat until golden and smelling fantastic. Pound to a powder in a pestle and mortar, then tip into a bowl. Trim the chillies (deseed if you like) and roughly chop with the lemongrass (use just the thick, lower part, discarding the outer layer), then peel and chop the galangal, garlic and shallots. Place it all in a pestle and mortar with 2 sprigs of coriander (stalks and all) and a good pinch of sea salt. Finely grate in the kaffir lime zest, then pound to a paste. Muddle in the shrimp paste, ground cumin and coriander, and white pepper (or whiz everything together in a food processor). Deseed the red chillies, finely slice at an angle and place in ice-cold water, ready for serving. Slice the chicken into 2cm strips. Drizzle 2 tablespoons of oil into a large heavy-bottomed pan on a medium-high heat. Add 3 heaped tablespoons of the curry paste (save the rest for another day) and a splash of coconut milk, then fry for 30 seconds, or until smelling fantastic, stirring continuously. Stir in the chicken, then, after 5 minutes, pour in the remaining coconut milk and bring to the boil, stirring regularly. Tear in the kaffir lime leaves and simmer for 10 minutes. Stir the palm sugar into the pan and have a taste; the curry should be slightly sweet, but not overpoweringly so. Add the fish sauce and taste again – it should taste well rounded, salty with an underlying sweetness. Quarter the aubergines and add to the pan to cook for 2 to 3 minutes (regular aubergines will take quite a bit longer, so cook until tender), then turn off the heat. Pick and stir in most of the Thai basil, then drain the chilli and sprinkle over with the remaining Thai basil and coriander. Delicious served with jasmine rice.