- Heat oil in a large nonstick skillet over medium-high heat. Add chopped celery, onion and bell pepper. Sprinkle with pepper and sauté 5 minutes or until tender.
- Transfer to a 5-quart slow cooker and add remaining ingredients except for beans and tortellini. Cover and cook on low for 4 hours.
- Increase heat to high; add beans and tortellini. Cover and cook 18 minutes or until beans and pasta are heated through. Garnish with cheese, if desired.