Wrap raw beef in plastic; chill in freezer for 30 minutes or until semi-firm. Slice as thin as possible (⅙ of an inch 0.1 cm. is ideal). If meat begins to defrost while slicing, place back in freezer until firm. (Meat sliced this way is routinely available at Asian markets.)
Soak the rice noodles in warm (80° to 90°F or 27° to 32°C) water until softened, about 30