Saffron, by weight the most expensive spice in the world, is a tiny but delicious spice that imparts its golden color to paella, risotto Milanese, Indian pilaus and Cornish saffron buns. Saffron has a strong bouquet, with the aroma of honey, and a pungent, bitter-honey flavor. Saffron comes from the fall-flowering saffron crocus, a mauve o