Heat a large nonstick skillet over medium-high. Coat pan with cooking spray. Add celery mixture, and sauté 5 minutes or until tender. Transfer mixture to a 5-quart slow cooker. Stir in pepper and next 5 ingredients. Cover and cook on LOW for 7 hours.
Step 2
Increase heat to HIGH; add tortellini. Cover and cook 18 minutes or until pasta is tender. Garnish, if desired.