1.Process sugar, 1 cup basil and chopped cucumber in a food processor until smooth.
2.Fill a large jug one-third full with crushed ice. Strain cucumber mixture through a fine sieve into jug, pushing down on solids to extract all liquid.
3.Add gin and juice; stir well to combine. Top with remaining basil and sliced cucumber to serve.
Use a vegetable peeler to thinly slice the cucumber lengthways.Note