1. Trim the tenderloin of excess fat and silver skin. In a food processor, combine the sea salt, peppercorns, garlic powder and mustard powder. Pulse until peppercorns are crushed into small pieces. Pour into a small bowl. Add 1 tablespoon of oil. Rub the mixture into the meat. Let the meat come to room temperature for 1 hour.
2. Wipe out the food processor. Add the thyme, sage, parsley, rosemary and red pepper flakes. Process until finely chopped. Transfer to a bowl. Stir in one tablespoon of oil. Set aside.
3. Preheat oven to 300° F. Heat a large skillet over medium-high heat. Add the remaining oil. When the skillet is hot, add the meat. Sear on all sides for about 3 minutes per side. After searing, set aside to cool. When meat is cool enough to handle, rub the herb mixture into the meat.
4. Place in a roasting pan. Cook until the internal temperature reaches 130° F for medium-rare or 140° F for medium. Cooking time will vary depending on thickness and degree of searing. Allow about 45 to 50 minutes for medium doneness. Remove the meat from the oven. Let the tenderloin rest for 15 minutes before slicing. Serve with horseradish sauce.

Per Serving: Calories: 470, Fat: 27 g (8 g Saturated Fat), Cholesterol: 155 mg, Sodium: 690 mg, Carbohydrates: 1 g, Fiber: 1 g, Protein: 56 g.