2 1/2 oz of Gin
1 1/2 oz of Lemon Juice
1 tsp of superfine sugar (or sugar)
4 oz of club soda (or clear soda)
1/2 oz of creme de cassis (or blackcurrant-flavored liqueur)
In a shaker half-filled with ice cubes, combine the gin, lemon juice, and sugar. Shake well. Strain into a collins glass almost filled with ice cubes. Add the club soda. Stir well. Drop the cassis into the centre of the drink.