Mul Naengmyeon

I used beef stock to make Naengmyeon.

The beef stock was made from 3.5 pounds of trimmed brisket. Let it sock in cold water for half an hour. Change the water and rinse the meat. Bring it to a boil for 10 minutes and change the water again. Bring it back to a slow boil and onion, garlic and black pepper corns cook until you can pierce the meat with a chop stick. Cool the stock and meat down and put in the refrigerator over night. Skim off any fat.

Mustard sauce was:
1 tablespoon dry spicy mustard
3 tablespoons rice vinegar
3 tablespoons sugar
1/2 teaspoon sea salt