Marinade chicken with half the lemongrass, oil, and 1 tsp fish sauce for 20 minutes.
Preheat the oven to 200°C.
Dissolve palm sugar with water in a casserole over low heat until syrupy.
Cool sugar for two minutes, add extra fish sauce and chicken, then sear for 8 minutes before oven finishing.
Heat a deep-fat fryer to 180°C.
Char the pierced aubergine over an open flame until the skin is burnt and the flesh is tender.
Gently heat vinaigrette ingredients with 460ml water in a pan.
Add chopped shallot and green spring onions to the vinaigrette.
Deep fry shallot rings until crisp and drain on kitchen roll.
Scoop aubergine flesh from the burnt skin and cut into bite-sized pieces.
Drain spring onions from the liquid, reserving the vinaigrette for dressing.
Garnish with spring onions, crispy shallots, and lime leaves before serving with chicken and rice.