In food processor or blender, purée stewed tomatoes. In large saucepan, bring pureed tomatoes, chicken broth, cumin and chicken breasts to boil. Simmer 8 to 10 minutes or until chicken is tender. Remove chicken pieces to clean cutting board and shred, using two forks. Divide chicken among 4 bowls; top with broken chips and shredded Monterey jack. Pour hot soup over and serve soup with limes, avocado, and cilantro, if desired.