Galangal noun

Galangal is a rhizome of the ginger family that gives tom yum, tom kha and most Thai curry pastes their distinctive fragrance. It is harder and denser than ginger and is never grated raw onto food.

Sharper and more citrus-pine than ginger, with a medicinal, peppery edge and almost no sweetness.

Slice thinly or bruise and simmer in soups and curries; it is rarely eaten, so remove before serving or warn the diner. Pound into curry pastes with lemongrass and coriander root. Do not substitute ginger one for one; the flavour is different.

Cultivated across Thailand, Laos and Indonesia for centuries, galangal appears in the earliest Thai kitchen records alongside lemongrass and kaffir lime. In Thai cooking it is treated as an aromatic, not a vegetable: its job is to perfume the broth.