Kaffir Lime Leaves (sometimes simply known as lime leaves) is an ingredient common in Thai and other Southeast Asian cuisine. It’s incredibly aromatic – just rub one leaf between your fingers and you’ll smell it’s sweet perfume immediately.
Kaffir limes are not the same as the standard limes you may be familiar with in the west. Kaffir limes are very bitter with a bumpy exterior and their leaves are highly aromatic.
The leaves are not meant to be consumed (unless they are finely chopped or thinly sliced). Generally they are muddled or bruised to release their aromatic properties and then removed before the dish is served, much like a Bay Leaf.
Unfortunately there is no good substitute for Kaffir Lime Leaves. Most Asian grocery stores will carry them and if all else fails… you can always find them online. Just make sure you get fresh, not dried leaves.