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