I have to confess that I am not generally a huge salad fan. There is nothing a hate more than a salad of lettuce soggy dressing and not much else. This salad is nothing like that. Crisp lettuce combined with plump grilled prawns and a tangy dressing make for a wonderful start to any meal.
Cut the stems and the roots from the cilantro very finely, setting aside the leaves. Combine the chopped cilantro with two cloves of garlic, light soy sauce, and 1 tablespoon of mirin. Pour the Marinade over the prawns and allow to marinade for one to two hours. Spray a fry pan with a little cooking spray and add the rest of the garlic and the ginger, fry until just cooked (about a minute). Add the Mirin, the fish sauce and cook for about a minute. Put the cilantro leaves in a food processor and blend with the garlic mixture until finely pureed, add the lime juice. Grill prawns until pink and just done (about four minutes). Brush with marinade as you are grilling. Combine the prawns with the lettuce and cucumber and toss over dressing. Serve immediately.