Smmer the meat in boiling water until nearly cooked through, remove from water and set aside. In a medium-sized pot, bring the coconut milk and curry paste to a simmer over medium low heat.
Allow to simmer for 5 minutes, stirring every minute. Add the fish sauce, brown sugar, water, vegetables, and onion and simmer until the vegetables are nearly done, (length of time depends on type of vegetable, i.e. potatoes take longer to cook through than mushrooms).