The Kaffir Lime leaves are an essential part of many South East Asian dishes likeTom Yum and Thai curries. It doesn’t really have a substitute. The dried leaves are easily available at large supermarkets but aren’t as strong as the fresh ones. The leaves have a citrusy, sharp aroma that adds to any dish they’re included in.
The Kaffir Lime fruit is extremely difficult to get outside of Asia. I get mine online.
I have had a kaffir lime plant for a long time but have never been able to get it to fruit. The furthest I’ve got is the white flowers. I guess you need constant warm and humid conditions.
The zest of the fruit is often used in curry pastes as in the Green Thai Curry.
The juice is believed to have medicinal properties and is in fact used in herbal concoctions. It is in fact, a little too strong and slightly bitter compared to other limes, which is why it’s not used as a garnish very often.