Thai green curry is a study in balance—the sweetness of coconut milk against the heat of green chillies, the aromatic complexity of curry paste against the clean simplicity of Thai basil. Get the balance right and you have something that tastes like it came from a Bangkok street stall. Get it wrong and you have coconut soup with chicken in it.
The key is good curry paste. Make your own if you have the time and a mortar and pestle. Buy the best quality jar you can afford if you do not. The difference between mediocre and excellent curry paste is the difference between a forgettable meal and one that makes you close your eyes when you taste it.
Coconut milk provides the base, but it needs balancing with fish sauce for saltiness, palm sugar for sweetness, and lime leaves for that distinctive Thai citrus note. The vegetables—bamboo shoots, Thai eggplant—add texture without overwhelming the curry. This is not a stew. The vegetables should still have bite.