Process avocado in a blender or food processor until mixture is smooth, stopping to scrape down sides. Add chopped cilantro and next 9 ingredients, and process until mixture is smooth, stopping to scrape down sides. Pour into a large bowl; stir in chicken broth and sour cream. Cover and chill 3 hours.
* 1 (16-ounce) container light sour cream may be substituted.
