1. Place beef, sweet potatoes, onions, apples, broth, garlic, salt, 1/2 tsp thyme and 1/2 tsp pepper in slow cooker. Cover; cook on LOW 8 to 9 hours.
2. Transfer beef, sweet potatoes and apples to platter; keep warm. Let liquid stand 5 minutes to allow fat to rise, skim off fat.
3. Combine cornstarch, remaining 1/2 tsp thyme, 1/4 tsp peppr, cinnamon and water; stir into cooking liquid. cook 15 minutes or until juices are thickened. Serve sauce with beef, sweet potatoes and apples.