Cut a thin slice from stem end of each bell pepper to remove top of pepper. Remove seeds and membranes; rinse peppers. If necessary, cut thin slice from bottom of each pepper so they stand up straight. In a 4-quart Dutch oven, add enough water to cover peppers. Heat to boiling; add peppers. Cook about 2 minutes; drain.
In a 10-inch skillet, cook beef and onion over medium heat 8 to 10 minutes, stirring occasionally, until beef is brown; drain. Stir in rice, salt, garlic and 1 cup of the tomato sauce; cook until hot.
Heat oven to 350 F.
Stuff peppers with beef mixture. Stand peppers upright in ungreased 8-inch square glass baking dish. Pour remaining tomato sauce over peppers.
Cover tightly with foil. Bake 10 minutes. Uncover and bake about 15 minutes longer or until peppers are tender. Sprinkle with cheese.