In a large skillet, cook sausage, green pepper, mushrooms and onion until meat is browned and vegetables are tender; drain. Place croutons in a greased 13-in. x 9-in. x 2-in. baking dish; top with sausage mixture. Beat eggs and milk; pour over sausage. Cover and chill for 8 hours or overnight. Remove from refrigerator 30 minutes before baking. Bake, uncovered, at 300 for 1 hour. Sprinkle with the mozzarella and cheddar cheeses. Place tomatoes over top; sprinkle with parmesan cheese. Bake 20 minutes longer or until a knife inserted near the center comes out clean. Let stand 5 minutes before cutting. Recipe by: Taste of Home Spring 97 Posted to MC-Recipe Digest V1 #527 by Daphne on Mar 20, 1997