In large saucepan over medium heat, sauté the onion and garlic in the Annatto Oil. Cook, stirring often, until the onion and garlic have softened, for about 5 minutes. Now add the rice and cook about 2 minutes, until most of the rice is coated with the oil and looks opaque.
Add the salt, and the water or stock, then bring to a boil. Give the rice a stir, then reduce heat to low, cover, and cook for 20 minutes. When the 20 minutes is up, taste the rice - if it's done, remove the pan from the heat, and let it stand (still covered) for a few more minutes. If using chopped cilantro, add it now, then fluff the rice with a fork, and serve.