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