Kesar
Saffron, the crimson threads of the crocus flower and the world's most expensive spice by weight.
Also: saffron, zafran, kumkuma poo, crocus stigmas
Kesar is saffron, the dried stigmas of Crocus sativus. Each flower yields only three threads, picked by hand at dawn in autumn, so a kilogram needs well over a hundred thousand blooms. The threads smell honeyed and hay-like and colour food golden. Kashmir's Pampore plateau, Iran, Spain and Greece are classic producers, and Iran grows the great majority of the world's supply. Cooks steep a few threads in warm milk or water before adding them to biryani, paella, risotto, kheer or milk sweets. Saffron is part of ritual in Hindu and Persian life. Beware cheap powders and dyed threads, since adulteration is common.