Herbs are super important in this traditional Spanish dish. Saffron is the main spice to use, when making Paella. Saffron is the most expensive spice on Earth and is the red-yellow stigma of the crocus flower and must be hand-picked during short annual flowering seasons. Each flower produces only three stigmas, so it takes approximately 150 flowers to yield just one gram of dry saffron.

Source: Julia Recipes