Heat the oil in a large pot over medium heat. Stir in the pepper and onion stir fry mix, garlic, and cumin, and cook 5 minutes, until vegetables are tender. Mix in the tomatoes and chile peppers. Pour in the broth, and season with salt and pepper. Bring to a boil, reduce heat to low, and simmer 30 minutes.
Mix corn into the soup, and continue cooking 5 minutes. Serve in bowls over equal amounts of tortilla chips. Top with cheese and avocado.