In a large slow cooker combine mushrooms, celery, carrots, onions, pepper, and garlic. Place chicken drumsticks on vegetables. In a small bowl combine broth, wine, tapioca, bay leaves, sugar, oregano, salt and pepper. Pour over mixture in cooker.
Cover and cook on low for 6-7 hours or on high 3-3 1/2 hours.
Transfer chicken to a serving platter. Cover and keep warm. Discard bay leaves. If using low heat setting, turn cooker to high heat. Stir in tomatoes and tomato paste. Cover and cook 15-20 minutes more.
Spoon vegetable mixture over chicken. Serve with hot cooked pasta. Top with shredded basil, if desired.