Cabbage Roll Casserole

2 pounds ground beef
1 cup chopped onion
29 ounce can tomato sauce
3 1/2 pounds chopped cabbage
1 cup uncooked white rice
1 tsp salt
2 - 14 ounce cans beef broth

Preheat oven to 350 degrees. In a large skillet, brown beef in oil over medium heat until redness is gone. Drain off fat. In a large mixing bowl combine the onion, tomato sauce, cabbage, rice, and salt, Add meat and mix all together. Pour mixture into a 9x13 inch baking dish. Pour broth over meat mixture and bake in the preheated oven, covered, for 1 hour. Stir, replace cover and bake for another 30 minutes.