Rinse beans; add 6 cups of water. Bring to a boil; simmer 5 minutes. Remove from heat; let stand, covered, 1 hour. Do not drain. After 1 hour cover, simmer 30 minutes. In Dutch oven, cook bacon til crisp. Drain, reserve drippings. Crumble bacon; set aside. Coat beef with flour. Brown beef in hot drippings, pour off excess fat. Stir in beans and onion. Combine toamto juice, brown sugar, salt, peper and mustard. Pour over beans and beef mizture. Bake covered in 160ºC . oven til tender, about 1.5 to 2 hours. Serve hot topped with crunbled bacon and grated cheese to taste.