Kaffir limes are indigenous to South Asia and have a pebbled skin and fragrant, hourglass-shaped leaves. Both the juice of the lime and the leaves are a key ingredient in Southeast Asian cuisines.We always keep a spice jar of kaffir leaves handy. The leaves can be used fresh or dried, and are used to impart flavor in soups, sauces, curries, and main dishes. The leaves can also be infused in vodka and made into a paste. We buy ours at the Alemany Farmer's Market, but they can also be purchased online at Import Foods. They can keep for several days in the refrigerator, but if you wait too long, they will turn brown. If you don't use the leaves right away, lay them out to air dry and then store them in a spice jar.