- Soak the wooden skewers in water (30 minutes).
- Cut the vegetables into square pieces.
- Whisk together everything in the ingredients list except the vegetables to make a marinade. Pour Marinade over vegetables. Cover and refrigerate for 2 hours.
- Preheat an outdoor grill to medium heat.
- Remove vegetables from the marinade, keeping the marinade off to the side. Thread vegetables onto skewers, alternating colors. Cook skewers on grill until vegetables are lightly charred all over, about 10 minutes, basting with reserved marinade and turning occasionally.