SHAKE all ingredients with ice and fine strain into chilled glass.
Orange zest twist
Disco blue but medium dry with a bittersweet orange taste.
Adapted from Harry Craddock's 1930 The Savoy Cocktail Book. His recipe called for ¼ triple sec liqueur, ¾ vodka and 1 dash blue food colouring. The Blue Monday also appears in Patrick Gavin Duffy’s 1934 The Official Mixer’s Manual.