Kaffir lime (magrood): A profusely fragrant tropical citrus, kaffir lime is indispensable in Thai cooking and cannot be substituted with other kinds of citrus. The valued parts are the leaves (bai magrood) and the peel (pew magrood) or zest of the limes. The juice is also aromatic but is not generally used in cooking since its perfumy quality can overpower light sour dishes. Both leaves and peel are available frozen or dried if you are not able to find them fresh and do not grow your own.