First, heat the butter and oil in a large pot then add the diced bell peppers and onion. Lightly season them with salt, pepper, cayenne pepper and chili powder. Sauté until the vegetables are soft.
Now stir in the tomato paste and cook for a minute or two. Then add in the chicken broth, corn, beans, rotisserie chicken and diced tomatoes.
Next add the sour cream and taco seasoning. Stir to combine everything and let it simmer on the stove for about 10 minutes.
Finally, transfer the soup into individually portioned out bowls and top with crushed tortilla chips, shredded cheddar cheese and sour cream. Enjoy!