Regans' Orange Bitters #6 is a brand of cocktail bitters, invented in the early 1990s by Gary Regan, a bartender who helped nurture the cocktail movement. The recipe includes orange peel, cardamom, and coriander along with the classic bittering agents: cinchona bark, quassia, and gentian root. Made in the style of pre prohibition orange bitters that had gone missing. A martini isn't one without a dash!