Gin Atomic

Select and pre-chill a highball glass.

Prepare a garnish by twisting a strip of lemon zest.

Lightly muddle the basil leaves in the base of a shaker, bruising them gently to release their aroma.

Add the Hayman's London Dry Gin, elderflower liqueur, freshly squeezed lemon juice, and optionally, a couple of dashes of Fee Brothers Lemon Bitters.

Shake the mixture with ice until well chilled.

Pour the Thomas Henry Tonic Water into the shaker, then fine strain the mixture into the pre-chilled, ice-filled highball glass.

Express the lemon zest twist over the cocktail and use it as a garnish.

Serve the cocktail with a straw.