Roasted Eggplant Soup with Bell Peppers

This is one of my oldest and most favorite soups. It originated as a clear tomato broth with slices of roasted eggplant and vegetables in it; the soup was transformed accidentally when I appeared as a guest chef in a restaurant in Chicago, and the kitchen staff decided it was easier to purée it. I found I liked it better their way too. The soup is particularly wonderful in the summer, when the bounty of peppers, eggplant, onions, and tomatoes bursts forth in our gardens and farm markets.