This is an Italian dish that was made up to use what's leftover-- yesterday's bread, and all those tomatoes and eggplants from a Summer garden. Add cubed mozzarella cheese or cooked white beans at the end to make it a complete meal. It could also be mixed with some kale (cut in a chiffonade, or ribbons) to make it more of a salad.
This is a great dish to have in your arsenal for a crowd of hungry breakfast guests. It's really easy, it's a "kitchen sink" kind of dish where you can use almost anything in it, and you prep it the night before so all you do in the A.M. is pop it in the oven.