The edible seed of the hazel tree (Corylus avellana), valued for its rich, buttery flavor and firm crunch. Also called a filbert, it has been eaten since prehistoric times, with cultivation believed to have begun near the Black Sea before spreading through the Mediterranean; today Turkey produces the majority of the world's supply, with Italy, the United States, and China also major producers. It appears in both sweet and savory cooking: toasted and ground into cakes, cookies, and pastries; whole or chopped as a coating for meat or a garnish for salads and roasted vegetables; or as the base of pastes such as gianduja. Its flavor, nutty with notes of caramel and chocolate, pairs naturally with chocolate, coffee, vanilla, and citrus.