Poor Man's Chop Suey

1 cup chopped onion
1 pound hamburger
2 cups celery, in chunks
1 can cream of mushroom soup
1 cup uncooked rice
1/3 cup soy sauce
2 cups hot water

Brown onion and hamburger; drain. Mix remaining ingredients and add the hamburger and onion mixture. Put into a casserole and bake at 350 degrees F for one hour or more.