I was taught this recipe by a Thai chef from the Royal Orchid restaurant on Portland Street, Manchester, England. I've tried dozens of recipes for this dish, and this is the best that I've ever been able to do it. Obviously, it's open to interpretation: if you want it a bit more salty, add a bit more nam pla; if you want it a little sweeter, add a touch more palm sugar; if it's not spicy enough, add more chilli to the paste. In addition, I'd always go for the full fat coconut milk - it gives a far better texture to the dish. I'm very much from the Gina D'Acampo school of thought on this one - don't try to make healthy options; just go to the gym. Also note that the veggies in this are interchangeable for several other things - interchange the aubergine and beans for any other types of green veg - sugarsnap peas, runner beans, peppers etc. Finally, I should also specify that the palm sugar should be dissolved in hot water before adding to the pot - this should be done entirely based upon taste, but as a starting point, I'd say that you should add a couple of tablespoons of sugar to 300ml of hot water.