Heat oil in a large saucepan over medium heat. Saute onions,carrots, and garlic until tender. Stir in green pepper, red pepper,celery, and chili powder. Cook until vegetables are tender, about 6minutes.Stir in mushrooms, and cook 4 minutes. Stir in tomatoes, kidneybeans, and corn. Season with cumin, oregano, and basil. Bring to aboil, and reduce heat to medium. Cover, and simmer for 20minutes, stirring occasionally.