4 cups of water
1 can of coconut milk
Cayenne pepper [or a pinch of red curry paste]
Bring the water and the juice from the limes to a boil. The limes can be tricky because there are times when I have only had to use the juice of 1/2 of a lime but tonight, I needed 1 and a half. Just make sure you test it as you go along. Add the coconut milk, pepper/curry paste, and add enough salt to taste. It is a good idea to let it all simmer together for at least 45 minutes. If the soup boils down too much and is too sour, just add more water. I added some dried shitake mushrooms and it rocked.