2. Rub the tenderloin with oil and sprinkle it with salt, black pepper and red pepper. Place it in a roasting pan, cover and chill for 8 hours.
3. Bake for 15 minutes or until browned. Lower temperature to 375°F and bake for 20 more minutes or until desired degree of doneness is reached. Let stand 10 minutes before slicing.
4. Meanwhile, combine the sour cream and horseradish in a small bowl. Season with salt and pepper.
5. Slice the beef on the bias. Serve with horseradish-sour cream and garnish with fresh herbs.