Krachai is actually what defines the gaeng pah taste. You needn't add galangal, it's not used in Thailand.
Don't make the mistake of reducing it too much, it is eaten as a soup, not as what we would define as a curry.
I love it, it's my favourite Thai 'curry', my wife needs to make it at least ince a week.
If you've a Thai grocery in your hometown then you could also add cha om. I think it's water acacia in English. Thais will understand, you need to look for youngish shoots, maybe 3- 4 inches long, get rid of the stems if they're too thick or have already developed thorns.
Here's cha om:
http://www.simply-thai.com/thai-veg-big-images/cha-om-vsm.jpg
Here's krachai:
http://www.uni-graz.at/~katzer/pictures/boes_01.jpg
And don't add coconut cream, it's not that sort of curry ;)
Edited by: HenningWessel
