Preheat large pot on medium heat and swirl oil to coat. Add onion, garlic, carrots, bell peppers and saute for 4 minutes, stirring occasionally. Add oregano, cumin, salt, pepper and cook for 30 more seconds, stirring frequently.
Add potatoes, zucchini, corn, green chilies, black beans, tomato sauce and vegetable stock. Stir, bring to a boil and cover. Reduce heat to low and simmer for 25 minutes or until potato is fork tender.