Coriander root

The root and the lower 20 mm of stem of Coriandrum sativum. A pounding ingredient in Thai cooking and almost never a garnish. It holds the same aldehydes as the leaf at a higher concentration, plus a woody earthy fraction the leaf does not have. Those compounds are much less volatile than the compounds of the leaf. So the root survives a fried paste and a 90 minute braise, where the leaf would be gone in minutes. Root and leaf are therefore two ingredients on one plant. Split the bunch: root to the mortar, leaf to the end of the cook. Scrub the root under water. Do not peel it. Supermarket coriander is often sold with the root cut off, so buy it from a Thai or Vietnamese shop where it is sold whole.