Thai Chicken Coconut Soup

Ingredients:

3 cn TO
Mushrooms
1 Carrot; grated
Juice from (8?) limes
I can never put in enough
Serrano chillies
OR- other hot chili pepper,
preferably fresh,
but powdered will do)
also cubed to bite size.
Chicken
4 cn Coconut milk
-(the unsweetened kind)
3 tb Chopped scallions
1 ts TO
3 ts Lemon grass
Cilantro (pref. fresh) *
Tofu
cubed into smallish pieces
1 ts Galanga powder

Method:

Heat the coconut milk in a pot.
Add everything else.
As the lemon grass is inedible, put it in a tea ball and immerse the ball in the soup so you can retrieve it later.
Cook until the chicken is done and the soup is hot (30 minutes?).
Taste to see if it needs more limes (it always does) or more hot peppers (it's better to start mild and build up to the desired level of spicyness).