IN a large saucepan or pot, heat the olive oil over medium heat.
STIR in the chorizo, onion, carrot, and garlic and cook, stirring occasionally, until the vegetables are softened, about 3 minutes.
STIR in the beans, broth, chiles, cumin, oregano, and salt and pepper to taste. Bring to a boil, reduce the heat to low, cover, and simmer 10 minutes.
ADD the zucchini and cook, uncovered, until tender, about 2 minutes more.
LADLE the chili into bowls, then top with the green onion, sour cream, cilantro, and avocado. Serve with lime wedges.