In a stockpot, combine undrained tomatoes, salsa, broth, barley, water and seasonings. Bring to a boil over high heat. Cover and reduce heat to low; simmer for 20 minutes, stirring occasionally.
Add beans, corn and chicken. Increase heat to high; bring to a boil. Cover and reduce heat to low. Simmer for another 5 minutes, or until barley is tender. Ladle into bowls.
Top with cheese and sour cream, if desired.