IBA official recipe includes:
Components
45 ml – Gin
15 ml – Vodka
7.5 ml – Lillet Blanc
Preparation
Pour all ingredients into a cocktail shaker filled with ice cubes. Shake and strain into a chilled cocktail glass.
* Notes – Standard garnish – Lemon Zest. Commonly served before dinner.
Enjoy ! ADB
The drink was popularised by author Ian Fleming (1908–1964) in his 1953 novel Casino Royale.