If you like Korean cold noodles, this is the authentic one.
http://www.maangchi.com/recipe/naengmyeon
You'll never thought of using so much mustard powder, pear, garlic and corn syrup. Also a hammer to break ice cubes! Nothing like what you had before in China in the late 1980's when cold noodles were a fad in Beijing's small alleys. They have largely disappeared since the 90's.
Whoever loves Korean food should save this clip.