Add corned beef, potatoes, celery, onion, carrots, and cabbage to your slow cooker.
Combine broth, Worcestershire sauce, pickling spice, garlic powder, paprika, salt, and pepper. Pour over mixture.
Cover and cook on low 8–10 hours or high 5–6 hours until tender.
Add cornstarch slurry in the final 30 minutes for thicker broth.
Garnish with parsley and serve hot.
