Make sauce - puree sour cream, parsley, horseradish, lemon juice, and salt in food processor. Transfer to bowl. Fold in whipped cream. Chill up to 4 hours.

Remove beef from frig 1 hr. Before roasting. Preheat oven to 450~. Place beef in foil lined pan. Combine oil and salt; brush over beef. Rub all over with crushed pepper. Roast 35 to 40 mins., until meat thermometer reaches 130~ for med-rare. Let stand 15 min. Or up to 2 hrs. Before slicing.

Slice beef and arrange on platter. Serve warm or at room temp with Horseradish Sauce.