Mix together the lemon zest and juice, oil, honey, cardamom seeds and chopped coriander in a shallow dish. Season with freshly ground black pepper. Add the chicken and toss to coat well, then cover and leave to marinate in the refrigerator for 1–2 hours. Soak 12 bamboo skewers in cold water (to prevent them from burning under the grill).
To make the pita crisps, preheat the grill to medium. Cut each pita bread across in half, then split into two layers. Mix together the oil, garlic and herbs and lightly brush each piece of pita on both sides with the oil mixture. Place the pita on the rack in a grill tray (you may need to do this in two batches). Grill for 4–5 minutes or until lightly browned and crisp, turning once. Place on a plate and keep warm, or transfer to a wire rack to cool.
Thread the chicken, pineapple and tomatoes alternately onto the skewers, dividing the ingredients evenly. Grill for 10–15 minutes, turning occasionally, until the chicken is cooked through and tender. Brush the kebabs regularly with the marinade to prevent them from drying out. Serve with the pita crisps.