In a large pot over medium heat, heat the olive oil. Add the diced onion and cook until softened and translucent, about 5 minutes.
Add the minced garlic and cook for another minute until fragrant.
Add the chicken pieces to the pot and cook until fully cooked through, about 5-7 minutes.
Stir in the white beans, diced green chiles, chicken broth, ground cumin, dried oregano, and chili powder. Bring to a simmer and let cook for 20 minutes.
Stir in the sour cream and heavy cream, and season with salt and pepper to taste. Cook for another 5 minutes until heated through.
Serve hot, garnished with additional toppings such as shredded cheese, chopped cilantro, and avocado slices if desired.