Peanut Crusted Beef

4 pounds top loin beef trimmed and cut lengthwise into 2 long pieces
1/2 cup dry mustard
1/4 cup warm water
1 cup crunchy peanut butter
2 cups chopped Spanish peanuts
salt and pepper to taste

Sear beef on grill.

Mix mustard, water and peanut butter; spread on all sides of beef. Sprinkle with chopped peanuts, pressing nuts into surface of beef, if necessary. Sprinkle with salt and pepper.

Place on a roasting pan in a 450 degree F oven and roast until desired doneness is indicated on meat thermometer. Let rest 15 minutes before slicing to serve.