PREPARATION:

1. Prepare grill for direct cooking.
2. Place garlic on 10-inch piece of foil; lightly spray with cooking spray. Seal foil well; grill over medium-low coals, turning frequently, about 20 minutes or until tender. Peel garlic. Cut zucchini lengthwise into 1/4-inch slices; lightly spray with cooking spray. Cut tomatoes in half lengthwise; remove seeds.
3. Grill tomatoes and peppers, skin-side down, over hot coals until blackened. Place peppers in paper bag; steam 5 minutes. Grill zucchini and corn on covered grill over medium coals 1 to 3 minutes on each side or until tender and lightly browned.
4. Remove skin from tomatoes and peppers. Cut corn off cob. Cut vegetables into bite-size pieces; toss with garlic and pesto. Keep warm.
5. Bring water to a boil; add salt and black pepper. Slowly stir in polenta; cook and stir over medium heat about 5 minutes or until creamy and thickened. Stir in cheese and butter; add additional water as needed to keep creamy consistency.
6. Spoon vegetables over polenta; serve immediately.