STIR all ingredients with ice and strain into chilled glass.
Orange zest twist
One of those drinks where the bitter oils from the orange zest twist are crucial to its fine balance.
Recipe adapted from 'Old Waldorf Bar Days' published 1931, which said of this drink, "The name of an American yacht which took care of one of Sir Thomas Lipton's early but seemingly endless Shamrocks'". (Shamrock being the name of Sir Thomas Lipton's fleet of America's Cup racing yachts.)