Peel the cucumber and slice it thinly. Peel the ginger and cut it into thin matchsticks.
Place the ginger in a bowl, add the cider vinegar, salt, quartered chilli, and oil. Whisk to emulsify the dressing.
Shell the prawns if needed.
Finely chop the Thai basil, lemon balm, or mint leaves.
Arrange the cucumber slices in a salad bowl. Pour the ginger dressing over, toss gently, then add the prawns and herbs. Mix and serve immediately for maximum freshness.
