- In a shallow dish, mix together olive oil, cumin, chopped cilantro, and lime juice.
- Season with salt and pepper.
- Add chicken, and mix well. Cover, and refrigerate for at least one hour.
- Preheat grill for high heat.
- Thread chicken, zucchini, onion, red bell pepper, and tomatoes onto skewers.
- Brush grill with oil, and arrange skewers on hot grate.
- Cook for approximately 10 minutes, or until chicken is cooked through, turning to cook evenly.