Beat eggs with hand beater in 2 1/2-quart bowl until light and fluffy.
Stir in broccoli, onion, 1/4 cup Parmesan cheese, the milk, salt, basil and garlic powder.
Pour into ungreased rectangular baking dish, 11 x 7 1/2 x 2 inches.
Arrange tomato slices on top; sprinkle with 1/4 cup Parmesan cheese.
Cook uncovered in 325Â° oven until set, 25 to 30 minutes.