Coat a large nonstick skillet with cooking spray; add oil & place over medium-high heat until hot. Add onions & garlic; saute 5 min. Or until tender. Add tomatoes, oregano, salt, pepper & bay leaf. Cover & cook about 25 min. Or until tomatoes are tender. Remove from heat. Discard bay leaf. Put tomato mixture in processor with knife blade. Process until smooth. Put into a 12 x 8 x2 in. Baking dish.
Dip eggplant slices in egg whites, dredge in breadcrumbs. Place on rack of a broiler pan coated with cooking spray; broil 4 inches from heat about 3 min. On each side. Arrange eggplant slices on tomato mixture; bake at 450 for 10 min. Sprinkle with cheese & bake an additional 5 min. Or until lightly browned.