In a large soup pot, heat olive oil and cook onions and bell peppers over medium heat until slightly tender, about 4-5 minutes. Add in the chicken, and sprinkle with taco seasoning and ranch seasoning. Stir and cook mixture until chicken is cooked through.Add the chicken broth, tomatoes, green chiles, black beans, and corn to the pot and bring to a boil. Reduce heat to low and allow to cook for 10 more minutes to allow flavors to blend. Top with avocado, cheese, and cilantro if desired. Enjoy!