Step 1

Heat oil in a large pot over medium heat. Add onion and cook, stirring occasionally, until softened, about 3 minutes. Add garlic and cook, stirring, for 1 minute. Add broth, tomatoes, chiles, tortillas, chili powder and cumin. Bring to a boil, stirring occasionally. Reduce heat to a simmer. Cover and cook for 20 minutes.

Step 2

Add chicken and cream cheese, stirring until the cream cheese is melted. Remove from heat. Combine shredded cheese and cornstarch in a small bowl and gradually add to the soup, stirring until melted. Return the pot to medium heat and cook until hot, 1 to 2 minutes. Serve the soup with cilantro, sour cream and/or guacamole, if desired.