Marinated Grilled Vegetable Kebabs

Whisk oil, vinegar, garlic, Italian seasoning, salt and pepper in a large bowl. Add tomatoes, mushrooms, zucchini and onion slices and toss well to coat. Marinate in the refrigerator for at least 1 hour and up to 4 hours.

Preheat grill to medium.

Remove the onions from the marinade and cut into quarters. Thread the vegetables onto eight 8-inch skewers. Grill, turning once, until tender, 12 to 15 minutes total. Drizzle with the remaining marinade, if desired.