Cook rice in 2 cups boiling water for 10 minutes, drain and set aside. In a large frying pan, cook ground beef, mushrooms, onion, and garlic for 10 minutes, or until beef is fully cooked, stirring frequently. Drain excess fat. Add Worcestershire sauce, salt and pepper. Stir in rice, tomato sauce, tomatoes, and sour cream. Using a large casserole dish (2 1/2 litre), alternate layers as follows: place a layer of cabbage at the bottom, beef mixture, cabbage, beef mixture, and cabbage on top. In a separate container, stir bread crumbs and margarine together and sprinkle on top of the casserole. Cover and bake at 350°F for approximately 45 minutes or until rice is tender and topping is golden brown.