Carob. The trees grow in many parts of Greece, but the pods (also known as St John's bread or locust beans) aren't eaten as often as they once were in the old days, when they were one of the few sweet things, along with honey, that people had at hand.
Commercially the pods are dried and ground into a flour that tastes somewhat like cocoa, and used in confectionery. The beans can also be made into a syrup (σιρόπι χαρουπιού, sirópi charoupioú) that is said to be extremely good for osteoporosis. Greece today is the 5th largest producer after Spain, Italy, Morocco and Portugal; they are also grown on Cyprus.
Image by Comrade Foot