One of the most common spices of mediaeval cookery, saffron is now too expensive to be used with such abandon, although it is an essential ingredient of the Provençal bouillabaisse, the Milanese risotto and Spanish rice dishes, such as the traditional paella. It is also widely used in Indian cookery, especially in rice dishes and biryani.
Saffron comes from the orange stigmas of a type of crocus flower. The plant is native to Asia and parts of Europe, but was also grown extensively in England at one time, and has given its name to the town of Saffron Walden.
Saffron is available either as the dried stigmas or as a powder. The former may be ground, crumbled or used whole before being mixed with hot stock or liquid as called for in a recipe, while the powder is simply infused in the liquid.