Mahlepi is the aromatic spice that derives from the kernel of the black or mahaleb cherry (Prunus mahaleb). The tree is native to Asia Minor and the spice is very popular in Turkey as well as Greece. Mahlepi is used mainly in holiday breadmaking and in some pastry. The kernels either have to be ground or boiled as an infusion and strained to obtain the most flavor. You can find it in Greek and Middle Eastern food shops all over the world. In the U.S., you can find it online at www.titanfoods.com.