Step 1

Peel one half of a cucumber, and slice a lime into eight wedges. In a highball glass, add three slices of peeled cucumber, 1 sprig rosemary, juice from a lime wedge and 1 ounce gin. Muddle with the back of a spoon.

Step 2

Strain through a mesh strainer into a second highball glass. Add several cubes of ice, and three slices of unpeeled cucumber. Top with remaining gin and tonic, and serve garnished with rosemary sprigs.