Primarily used in Latin and Caribbean cooking, annatto seeds are also used to make achiote oil, which is often used in rice dishes and stews. To make achiote oil, cook annatto seeds in hot oil until their skin dissolves. Once the oil turns bright yellow, discard the seeds and use the oil for cooking. Annatto seed makes a much cheaper substitute for saffron's golden coloring; but it does not replicate saffron’s distinct flavor.
The seeds can also be made into adobo paste - grind them with garlic and any variety of chili pepper.