Place a handful of ice cubes in a Highball glass. Refrigerate and pour in 25 ml of your favorite gin and 10 ml of Fino Sherry de Jerez.
Then add 3 generous squirts of olive brine before topping up with London Essence Grapefruit & Rosemary Tonic Water.
To finish your Mediterranean in style, garnish it with an elegant twist of lemon zest.