Cut steak into serving pieces. Combine flour, salt and pepper; pound into steak with tenderizing mallet. Heat shortening in large skillet. Add steak; saute until well browned on both sides. Arrange in large, shallow baking dish; place onion rings and olives over steak. Combine tomatoes, meat sauce, bay leaf, brown sugar and thyme leaves in saucepan; mix well. Bring to a boil, breaking up tomatoes with back of spoon. Pour over steak; cover. Bake in 350 degree oven for 1-½ hours or until steak is fork tender. Skim off excess fat before serving.