Rub flank steak with halved garlic. Place steak on grill about 4 inches from coals and cook until browned outside, still rare inside. Remove from grill and thinly slice against grain. Combine butter, basil, minced garlic, salt and lemon juice in bowl and mash with fork to blend. Chill 15 minutes or until firm. Meanwhile, place French bread, sliced side down, on grill and toast 2 to 3 minutes. Remove from grill. Spread butter oveer bread. Top each with half of bread. Close sandwiches.