Preheat oven to 375F. Season tomato slices with pepper and set aside. Place bread crumbs, cheese and Italian seasoning in a large, resealable plastic bag. Working in batches, dip the mushroom and tomato slices in egg white, and place in the bag. Shake to coat. Arrange on greased baking sheet
. Spray vegetables with cooking spray. Bake
5 to 7 minutes. Turn, and coat with more cooking spray. Bake another 5 to 7 minutes or until golden and mushrooms are tender. Serve with Caesar or ranch dressing as a dipping sauce, if desired.