Variation: Slow Cooker Version
Omit olive oil. In a 3-1/2- to 4-quart slow cooker combine onion, celery, carrot, garlic, broth, squash, tomatoes, beans and dried oregano (if using). Cover and cook on low-heat setting for 7 to 8 hours or on high-heat setting for 3-1/2 to 4 hours. If using low-heat setting, turn cooker to high-heat setting. Add zucchini, broccoli, fresh oregano (if using), salt and pepper. Cover and cook 30 minutes more. Serve as above.