Mix celery, onion, mushrooms and butter in 2 quart casserole, cover. Microwave on high 6-8 minutes, or until tender-crisp. Set aside. In 2 cup measure, combine water, soy sauce, cornstarch, bouillon and sugar. Microwave on high 2 minutes or until thickened, stirring twice during cooking. Mix sauce and remaining ingredients with celery mixture. Microwave at high 4 6 minutes or until thoroughly heated, stirring after half the time. Serve over rice or chow mein noodles.