Mahleb or Mahlab is an aromatic spice made from the seeds of a species of cherry, Prunus mahaleb (the Mahaleb or St Lucie cherry). The cherry stones are cracked to extract the seed kernel, which is about 5 mm diameter, soft and chewy on extraction.
 
Mahleb is used in small quantities to sharpen sweet foods and cakes, and is used in production of tresse cheese.