Chicken, Tomato, and Tarragon Soup

When it is still summer and you have perfect tomatoes, this soup can do without the onion, bacon, and cream. But when there is a nip in the air, the bacon and cream will give it welcome substance. A slice of toasted bread, rubbed with a little garlic and placed in the bowl before ladling in the soup, makes a nice counterpoint by providing a contrasting texture.