Heat oil in a large saucepan over medium-high heat. Add onion; saute 5 minutes. Add broth, tomatoes and salsa; bring to a boil. Reduce heat; simmer uncovered 10 minutes or until onion is tender, stirring once.
Arrange chicken, cabbage and avocado in bottom of four shallow soup bowls. Ladle broth over chicken mixture; top with cheese, chips and, if desired, cilantro.
Leftover cooked chicken breast may replace the rotisserie chicken breast and Monterey jack cheese may replace Chihuahua.
Culinary Taste Tip
The chicken broth coupled with the water from the can of fire roasted tomatoes works as a delicious base for this soup.
Culinary Technique Tip
This recipe is a great way to use leftover chicken, especially rotisserie chicken.