1Cook rice according to directions; set aside. Measure out 1 1/2 cups of tomato sauce; set aside.
Preheat oven to 375 degrees.
2In a large skillet, cook beef, onion and garlic over medium heat until meat is no longer pink; drain. Stir in remaining tomato sauce, diced tomatoes with juice and seasonings. Bring to a boil. Reduce heat; cover and simmer for 5 minutes. Stir in cooked rice, bacon and mushrooms; heat through. Remove from heat.
3In a greased 13 x 9 x 2 baking dish, layer a third of the cabbage. Top with half of the meat mixture. Repeat layers; top with remaining cabbage. Pour reserved tomato sauce over top.
4Cover and bake for 45 minutes. Uncover; sprinkle with cheese. Bake uncovered 10 minutes longer or until cheese is melted. Let stand about 5 - 10 minutes before serving.