3/4 oz of Brandy
3/4 oz of Gin
3/4 oz of dry vermouth
1 twist of lemon
carbonated water (or sparkling water)
Pour brandy, gin, and dry vermouth into a highball glass over ice cubes. Fill with carbonated water and stir. Add the twist of lemon and serve. (Ginger ale may be substituted for carbonated water, if preferred.)