Though it has the air of a pre-Prohibition cocktail, the Cloister actually originates with the Playboy Bartender’s Guide, published in 1971. A gin sour that relies on two types of citrus, its monastic name is a nod to its inclusion of yellow Chartreuse, the complex herbal liqueur produced by the Carthusian monks of southeastern France. For New Orleans bartender Christina Rando, It’s the ideal “gateway” drink capable of converting skeptics into avowed Chartreuse fans. She prefers this variation from Jim Meehan’s 2011 PDT Cocktail Book, which introduces a touch of simple syrup to counterbalance the fresh grapefruit and lemon.