Place the cherries, sugar and tarragon in a small pan with 450ml of water. Gently bring to the boil, stirring until the sugar dissolves, then simmer for 10 minutes until the cherries are very soft.
Remove from the heat, then passthrough a sieve to remove the stones and the tarragon and puree the cherries. Stir in the lime juice, then chill until ready to serve.
Transfer to a jug and top with the soda water. Pour into ice-filled glasses and serve garnished with lime twists and fresh cherries.
- 400g fresh cherries plus extra for garnish
- 50g caster sugar
- 1 sprig fresh tarragon
- juice of 2 limes
- 600ml of soda water
- ice and lime twists, to serve