Heat a large nonstick skillet coated with cooking spray over medium heat; add sausage and cook until no longer pink, remove from pan. Add onion and next 4 ingredients (onion through mushrooms) to hot pan, adding more cooking spray as needed. Cover and cook 7 minutes or until tender, stirring mixture occasionally. Increase heat to medium-high; uncover and cook for 2 minutes or until liquid evaporates. Add chicken sausage back to mushroom mixture, season with pepper. Spread half of mushroom mixture in bottom of a 9X13 baking dish coated with cooking spray. Arrange half of eggplant slices over mushroom mixture. Top with 1/2 cup tomato sauce and 1/3 cup mozzarella and 2 tablespoons parmesan. Spread remaining mushroom mixture over mozzarella; top with remaining eggplant slices. Top with remaining tomato sauce. Sprinkle with remaining 1/3 cup mozzarella and remaining 2 tablespoons of parmesan. Cover and bake at 375° for 1 hour. Remove cover and continue baking for 5 minutes or until cheese melts. Let stand 10 minutes.