Annatto Seed Annatto seed is popular in Indian and Hispanic cuisines because of its bitter, earthy flavoring and the rich saffron hue it imparts. Combine with garlic, oregano, vinegar and a choice of other spices to create achiote paste, a pungent Latin rub used on meats and seafood to give a rich mahogany glaze. Annatto seeds are also found in tamales, stews and rice dishes.