Kaffir lime

❸ This small tree, with shiny, dark pointed green leaves, bears fruit that look like small green lemons, with noticeably wrinkled skins. Leaves and fruit are imported into Britain from Thailand and are usually available in Thai shops and some supermarkets. The juice (what there is) and rind, but more especially the leaves, are used in cooking; they give a characteristic citrusy flavour, and the juice, as one would expect, is particularly sour. Curry leaves or even bay leaves are just about acceptable as substitutes if the real thing cannot be found. Bay leaves are stronger and one bay leaf will replace 2-3 kaffir lime leaves.