Fry bacon until crisp. Crumble and set aside. In same pan, using bacon drippings, add celery and mushrooms. Fry until tender.
In a separate bowl, stir together the boiling water, tomatoes, soup mix, rice and 1/4 cup of cheese. Add celery and mushroom mixture as well as the crumbled bacon. Mix it all together and put in a 2 quart baking dish.
Cover with remaining cheese and bake at 375 F for 30 minutes or until rice is tender.