HEAT dressing in large skillet on medium heat. Add onion; cook 5 min. or until tender. Add eggplant; cook and stir 5 min. Add zucchini, pepper and mushrooms; cook and stir 5 min.
ADD tomatoes, bring to boil. Reduce heat to low; cover. Simmer 15 min. or until vegetables are tender, stirring occasionally. Pour mixture into casserole dish; sprinkle with cheese. Cover and refrigerate until ready to serve.
PREHEAT oven to 350°F. Bake 25 to 30 min. or until heated through. Sprinkle with parsley just before serving.