Remove fat from chicken. In 3 1/2- to 6-quart slow cooker, mix remaining ingredients except mushrooms, tomatoes, basil and cheese. Add chicken.
Cover and cook on Low heat setting 5 to 6 hours.
Remove chicken from cooker; place on cutting board. Use 2 forks to pull chicken into shreds. Return chicken to cooker. Stir in mushrooms and tomatoes. Cover and cook on Low heat setting about 15 minutes or until heated through. Sprinkle with basil. Serve with cheese.