1. Wash the mutton with water and cut the mutton into wide strips with a knife. Then wrap the mutton tightly with plastic wrap and place it in the freezer of the refrigerator for 1 hour (-18 degrees). Wait until the meat is completely frozen and the surface is frozen solid before cutting. Then take out and tear off the plastic wrap. When cutting, the knife edge must be sharp so that you can cut thinly. It needs to be almost thin before it can be rolled up.