Heat olive oil in a large pot over medium-high heat. Add diced onion and sauté for about 4 minutes until soft and translucent.

Stir in minced garlic and cook for another 30 seconds until fragrant.

Pour in chicken broth and add drained white beans, mild green chiles, and diced chicken breasts. Mix in corn, chili powder, ground cumin, dried oregano. Bring to a boil.

Reduce heat to low and cover the pot. Let it simmer for about 10 minutes until the chicken is cooked through.

Temper sour cream by mixing it with hot chili broth until smooth. Stir this mixture into the pot.

Adjust consistency by adding cornmeal or more broth as desired, simmering a few more minutes.