A Greek Christmas tradition, Christopsomo translates as "bread of Christ." Some families decorate the bread with a cross or "X." The letter "X" is the first letter in the Greek word for Christ and was used as an early abbreviation. Hence "Xmas."
Mastic gum, also called mastiha, is the dried resin of a Mediterranean tree. Grind it on a microplane zester or in a spice grinder.Christopsomo can be stored, wrapped in plastic, at room temperature for up to 3 days.