A pungent, dark-brown dried shrimp paste. It’s an essential ingredient in South East Asian cooking, particularly Thailand, and is used in very small amounts in soups and curries.
Available in Asian supermarkets, it’s sold in tins or jars, or as hard slabs or cakes.
While fish sauce can be used without further cooking, shrimp pastes such as blachan (which also give savoury saltiness to dishes) are always cooked. Typically they are fried or grilled, either alone or as part of a spice paste, until fragrant, before being combined with other ingredients.