3/4 oz of Gin
1/2 tsp of Maraschino liqueur (or cherry liqueur)
1 tsp of grapefruit juice
1 dash of bitters
1 oz of dry vermouth
Pour vermouth, gin, maraschino, grapefruit juice and bitters into a cocktail shaker half-filled with ice cubes. Shake well, strain into a cocktail glass, and serve.