In a large pot, heat a tablespoon of oil over medium heat. Add the diced chicken and cook until browned and cooked through, about 5-7 minutes.

Add the chopped onion, garlic, green bell pepper, and jalapeño to the pot. Sauté for about 5 minutes until the vegetables are softened.

Stir in the white beans, chicken broth, cumin, chili powder, oregano, salt, and black pepper. Bring to a boil.

Reduce the heat to low and let the chili simmer for about 20 minutes, allowing the flavors to meld.

Serve hot, topped with a dollop of sour cream if desired.