1-First Step: Prep and Season the Day Before* Pat the beef tenderloin dry with paper towels. Drying the surface helps browning and crust formation.* Tie the roast with butcher’s twine every 2 to 3 inches along its length for even cooking and a uniform shape. If using a whole tenderloin, trim silver skin and excess fat before tying.* Drizzle 1 tablespoon olive oil over the surface and rub to coat evenly.* Season generously with kosher salt and ground black pepper. Use roughly 1 teaspoon salt per pound as a guideline (about 1 to 1 1/4 teaspoons per 3-pound roast).* Sprinkle 1 tablespoon finely chopped fresh rosemary and 1 tablespoon finely chopped fresh thyme leaves evenly over the roast.* Place the seasoned tenderloin on a foil-lined baking sheet set on a wire rack. Refrigerate uncovered overnight. This step creates a drier surface for a better crust and concentrates flavor.

2-Second Step: Bring to Room Temperature and Preheat* Remove the roast from the refrigerator and let it sit on the counter for about 2 hours to come to room temperature. This helps the roast cook evenly.* Preheat your oven to 225 degrees F with a rack in the center position.

3-Third Step: Butter and Start Roasting Low* Dot the top of the tenderloin with 2 tablespoons cold unsalted butter, cut into small cubes. Set the roast in the preheated oven.* Roast at 225 degrees F for about 60 to 70 minutes, or until the internal temperature reaches 115 to 120 degrees F. Insert a probe thermometer into the thickest part without opening the oven to monitor temperature accurately.

4-Fourth Step: High-Heat Finish* Increase oven temperature to 450 degrees F. Continue roasting at this high heat for 10 to 15 minutes until the internal temperature reaches about 130 degrees F for medium-rare doneness.* Pull the tenderloin from the oven and tent loosely with foil. Rest for 10 minutes to allow juices to redistribute while residual heat carries the roast up a few degrees.

5-Final Step: Slice and Serve* After resting, remove the butcher’s twine and slice the roast into 1 1/2-inch thick steaks. Arrange on a warm platter.* Serve with a creamy horseradish sauce (mix sour cream, prepared horseradish, and Dijon mustard) and your choice of sides like creamy mashed potatoes, Boursin mashed cauliflower, roasted vegetables, or a mixed green salad with red wine vinaigrette.