I've rated this medium difficulty simply because it takes a while to prep. Also, it is important that you watch the soup as it is cooking to ensure that it not boil. Your coconut milk will curdle if boiled or covered during cooking. You should taste this soup several times along the way to make sure that it is to your liking. All ingredients can be adjusted accordingly. By all means, use Kafir Lime leaves; do not use other varieties of lime leaf. If you cannot get Kafir Lime leaves, just omit. The flavor will be altered significantly but still make a good soup. Likewise, as I have noted, ginger is a poor substitute for galangal, but I think it still makes a GREAT tasting soup. Again, the flavor is altered significantly, so used galangal if it is available. Note: cooking and prep times are approximate and should be used as a guideline only. I have simmered this soup on a VERY low heat for much longer than an hour but also cooked it in less than an hour.
large kafir lime leaves (do not use any other type of lime leaf)
stalks of lemon grass
panang curry paste
chicken, skinned and deboned (save these to make broth), cut into pieces
red chillies (thai if possible), bruised but whole
large onion (or 2 small) quartered
knob of ginger, sliced - (i used a piece about 2 inches long and about 1 inch in diameter) note: ginger is a poor substitute for galangal, but it still makes an amazing soup. it is very hard for me to get galangal here, so i use ginger.
fresh mushrooms, quartered or sliced depending on size i used button, but it would be even better with shitake or straw mushrooms.
cilantro leaves, sliced red chillies, red chilli flakes, nam pla (fish sauce) for diners to add to taste when served
It is helpful to prep everything in advance. Cover the chicken bones and skin with the water and put on on medium to low heat to make broth for soup. Take off the outer layers of the lemon grass and cut off and discard the root end and about the first two inches of the top end. Finely mince the white part of the root end and cut the rest into 1-2 inch sections. (That part is not edible but imparts a great flavor.) Roll the lime leaves to release the oils and the flavor. (Again, these are not edible but impart amazing flavor. Do not use other types of lime leaves.) Quarter onion. Peel and slice ginger. Slice or quarter mushrooms. Cut off stem ends of chillies and smash to bruise. After the broth is done, put all ingredients into a soup pot and cook on low to medium-low heat until chicken is done. Do not allow to boil or cover the pot or the coconut milk will curdle.