Heat olive oil in a large nonstick skillet over medium heat. Add onion, peppers, and garlic. Cook about 5 minutes or until tender. Add turkey, chili powder and oregano, cook until turkey is slightly browned, stirring occasionally to prevent sticking. Add the squash, beans, tomatoes, broth, salt and pepper. Cover and cook over low heat for about 15 minutes until squash is soft, checking to make sure there is enough fluid to prevent sticking. Serve with cornbread.