In a large bowl, coat chicken with jerk seasoning and half the lime juice; cover and refrigerate overnight (or for a minimum of 4 hours).
Soak skewers in water and preheat gas barbecue to high; adjust to medium after about 15 minutes. Thread chicken onto skewers. (Alternate chicken with mango and pepper, if using.) Grill until cooked through (6 to 8 minutes), turning occasionally.
Meanwhile, grill tomatoes, cut side down, for 2 to 3 minutes, then turn to finish them off. Toss tomatoes with greens, cucumber, coriander and onion. Drizzle with a little olive oil and remaining lime juice. Season with freshly ground pepper.
Per serving: , 237 calories, 30 g protein, 6 g total fat (1 g saturated fat), 15 g carbohydrates, 3 g fibre, 72 mg cholesterol, 213 mg sodium