To prepare the marinated vegetables, combine first 9 ingredients in a large zip-top plastic bag; add mushrooms and next 4 ingredients (mushrooms through zucchini) to bag. Seal and marinate at room temperature for 2 hours, turning bag occasionally. Remove vegetables from bag; discard marinade.
Preheat oven to 400°.
Arrange marinated vegetables in a single layer in a shallow roasting pan coated with cooking spray. Bake at 400° for 25 minutes or until tender, stirring occasionally. Remove from pan; cool. Chop vegetables, and place in a large bowl; stir in tomato and bell peppers. Line each pita half with a cheese slice; fill each with 1/2 cup vegetable mixture.
