Barley is high in fiber, recommended for diverticulosis. If the soup becomes thick the next day, you can thin it out with some broth or water.
In a large soup pot, heat olive oil over medium-high heat. Cook carrots and onion, stirring occasionally for about 5 minutes. Add mushrooms and cook, stirring frequently until mushrooms are tender, about 5 minutes. Add ham and cook stirring constantly for 1-2 minutes. Stir in chicken broth, tomatoes and barley. Bring pot to a boil, then reduce heat and simmer covered, until barley is tender, about 20 minutes.