Cook bacon, 5 slices at a time, in a large wok until crisp. Remove bacon and all but 3 Tblsp. of bacon drippings. Stir fry onion and celery in bacon drippings until almost tender. Add mushrooms, rice and soy sauce. Cook 5 minutes over low heat, stirrring occasionally. Stir in egg and cook only until egg is set. Turn onto a serving dish. Crumble bacon over top and serve immediately.