3-5 lb. (or more) beef or pork tenderloin
1 jar stone ground mustard (9 oz.)
Kosher rock salt

Best to have loin at about room temperature. Completely cover meat with 1 jar of stone ground coarse mustard. Sprinkle with 2-3 tbsp. kosher rock salt. Place on grill for about 15 to 20 minutes on first side, turn and grill another 10 to 15 minutes until meat thermometer reaches 160 degrees. Slice and serve. Can also be used on chicken or fish!