For the curry paste, dry roast the coriander seeds on a delicate flame in a heavy cast iron or just the heaviest pan you have, they should slowly start to smell fragrant but don't rush this process, they should gently roast but not burn. Add in the chillies and turn the flame off so they just roast with the heat of the pan.
Take them off the stove and add all the ingredients for the curry paste into a blender. Mix into a fine paste and add a bit of the coconut milk if it isn't easy to mix.
In a heavy cast iron or earthenware casserole, warm a few good tablespoons of coconut oil and when it starts to warm, add in your curry paste (taste it to see how strong you want the curry, I like it to be a bright ochre and quite spicy but it can also be used for a more delicate curry, in which case I would probably add in some lemon or more tamarind).
Cook out the curry paste a bit, the yellow should turn a dark golden, the heat should be low. Add in the chillies and coconut milk, as well as the salt and sugar (it could also be agave or molasses). Let the curry simmer and come nearly to a boil, then cover it and turn off the stove.
You could serve it just like this with fresh coriander and some red rice on the side. But it is also delicious with vegetables cooked in the curry (sweet potatoes, yams, pumpkin...and absolutely divine with mushrooms in it!)