Remove fat from chicken. Cut chicken into 1-inch pieces. In 10-inch skillet, heat oil over medium-high heat. Cook chicken in oil about 5 minutes, turning once, until brown.
In 3 1/2- to 6-quart slow cooker, place carrots, celery, onion, garlic and water chestnuts. Add chicken. In small bowl, mix broth, soy sauce and gingerroot; pour over chicken.
Cover and cook on Low heat setting 6 to 8 hours.
In small bowl, mix cornstarch and water until smooth; stir into chicken mixture. Stir in mushrooms and pea pods. Increase heat setting to High. Cover and cook 15 minutes. Serve over noodles.