Sweat onion, ginger, kaffir lime leaves, lemon grass, and curry paste in oil over medium heat until the onions are translucent. Add coconut milk and fish sauce. Cook on low heat for 30 minutes. Season with salt and strain through a fine mesh strainer.
This recipe is from the Beach House Grill at the Chatham Bars Inn and also appeared in the 2011 August issue of Cape Cod LIFE.