POUR 1/4 cup of the dressing into large skillet. Add onions; cook and stir on medium heat until crisp-tender.
ADD zucchini; cook and stir 2 min. Add eggplant; cook an additional 2 min. Add remaining 1/4 cup dressing and the tomatoes. Bring just to boil. Reduce heat to medium-low; continue cooking 10 min. or until vegetables are tender.
SPRINKLE with cheese. Serve with rice.