Melt butter in a large saucepan over medium-high heat. Sauté onion and garlic until translucent, 3 to 4 minutes. Add chicken, chiles, and cumin.

Cook until flavors are blended, about 1 minute. Stir in soup, and half-and-half until well combined. Continue to cook until heated through, about 5 minutes.

Ladle soup into bowls; top with cheese, and a dollop of sour cream.