In a large pot over high heat, brown the meat in the oil. Season with salt and pepper. Add the onion and cook for 3 minutes while stirring. Add the coconut milk, curry paste, lime, fish sauce, sugar and cinnamon. Bring to a boil. Cover and simmer over low heat for 2 hours or until the meat is fork tender. Remove the lime from the pot and compost. Freeze at this point, if desired.