Summer Basil and Tomato Bread Soup

There are many versions of this Italian soup, all with varying proportions of tomatoes, bread, and broth. Once you start adding a lot of bread, it’s hard to tell what it is—soup, casserole, or salad. Like all soups that rely on tomatoes for most of their character and flavor, I make this dish only in summer. You can serve this soup either hot or cold.