You can use chicken thighs (as I do) or chicken drumsticks, or a whole chicken cut up, it is quite versatile really. It is important to use a yellow capsicum, it seems to have the right amount of acidity for the recipie. If you don't have any fresh tomatoes handy you can easily leave it out, and if you dont have any tomatoe puree, you can use canned tomatoes, but make sure you drain the juice off.
If you like fresh coriander, add about 1/2 a bunch to the curry paste and blend with the other ingredients. As always, adjust the chilli, garlic and ginger to your taste. If found it did not need any salt and pepper, but taste and adjust accordingly.
If you want a good curry one of the secrets is to cook the curry paste really well, you want the onions and pepper to fry with the paste until the oil splits from it if possible.