COOK onions in hot oil in large skillet on medium heat 10 min. or until lightly browned, stirring occasionally. Add eggplant; cook and stir 5 min. Add zucchini, peppers and garlic; cook and stir 5 min.
ADD tomatoes, dressing and thyme; bring to boil. Cover; simmer on low heat 30 min. or until vegetables are tender, stirring occasionally.
SERVE topped with cheese.