If you happen to spot glossy, deep green fresh makrut lime leaves in a well-stocked produce section or Asian market, buy a handful. When cut, rubbed, or crushed, makrut (also called Kieffer) lime leaves exude a marvelous, complex citrus aroma that is at once terribly familiar and ― unless you know what it is ― unidentifiable. In Thai, Indonesian, Malaysian, and Vietnamese cooking, the leaves play an important role in seasoning soups, curries, salads, and other dishes. John Beardsley, chef at San Francisco's Ponzu restaurant, makes good use of the leaves, following both Southeast Asian traditions and his own creative direction, as in the dressing for this refreshing honeydew and cantaloupe salad.
You can order fresh makrut lime leaves from Uwajimaya (800/889-1928 or firstname.lastname@example.org). They can be frozen for two to three months.