Saffron. Known as the most expensive spice in the world, each reddish-gold shred is a crocus stigma. The saffron crocus has only three stigmas which are hand-gathered and dried. The best saffron comes from Spain and Iran. Very little is needed when preparing a recipe and it is a must for colouring and flavouring rice in the Arab world. In the gulf it is also an important flavouring agent for gah-wa, breads and custard.