1. Combine the sugar and water in a large saucepan and place over a high heat just until the sugar has dissolved. Remove from the heat and pour the syrup into a jug. Allow it to cool to room temperature.
2. Stir the lemon and orange juice into the syrup and refrigerate until very cold.
3. Add some ice cubes, lemon slices and/or mint leaves to garnish, then serve.

Per serving: 180kcals, 0.4g fat (0g saturated), 46.1g carbs, 45.5g sugars, 0.6g protein, 0.7g fibre, 0.008g sodium