Heat oil in a large skillet over medium heat; add chicken and onion. Sauté 10 minutes or until chicken is done; set aside.
Combine broth, beans, chiles and seasonings in a large Dutch oven. Bring to a boil over medium-high heat. Add chicken mixture; reduce heat and simmer 30 minutes. Add sour cream and whipping cream, stirring well.
Top each with shredded cheese; garnish, if desired.