Cut eggplant into 1/4-inch slices; cook in a small amount of boiling water for 5 to 10 minutes or until eggplant is tender. Drain well.
Place eggplant in a lightly greased 13- x 9- x 2-inch baking dish. Place tomato slices on top of eggplant. Combine green pepper, onion, salt, pepper, and garlic powder; sprinkle evenly over tomato slices. Cover and bake at 400° for 20 minutes; reduce heat to 350° and bake, uncovered, an additional 35 minutes.
Arrange cheese slices on top during last 10 minutes of baking time.