Prepare the marinade: In a small bowl, combine olive oil, balsamic vinegar, garlic powder, oregano, basil, salt, and pepper. Whisk together until well combined.
- Prep the vegetables: Cut all the vegetables into even pieces to ensure they cook evenly on the grill. If using wooden skewers, soak them in water for 10-15 minutes to prevent them from burning.
- Marinate the vegetables: Place the chopped vegetables into a large bowl and pour the marinade over them. Toss the vegetables gently to coat them evenly. Let them marinate for at least 15-20 minutes, or up to 1 hour for more intense flavor.
- Assemble the kabobs: Thread the marinated vegetables onto the skewers, alternating the veggies to create a colorful, even mix. Be sure to leave a little space between the pieces to allow them to cook properly.
- Grill the kabobs: Preheat your grill to medium-high heat. Lightly oil the grill grates to prevent sticking. Place the kabobs on the grill and cook for 8-10 minutes, turning occasionally, until the vegetables are tender and lightly charred.
- Serve: Remove the kabobs from the grill and garnish with fresh parsley if desired. Serve immediately as a side dish or with a dipping sauce like tzatziki or hummus.