Remove the beef tenderloin from the refrigerator 1 hour before roasting. This helps it come to room temperature, ensuring even cooking.
Trim and tie the beef tenderloin. This helps maintain its shape while roasting.
Preheat your oven to 500˚F, placing a rack in the center. This high heat will create a nice crust on the outside.
Coarsely chop the garlic cloves. Then, strip the fresh thyme leaves and fresh rosemary leaves off their stems. Finely mince the garlic and herbs together.
In a small mixing bowl, combine the minced garlic and herbs. Add unsalted butter, prepared horseradish, salt, and black pepper. Use a fork to mash everything together until well combined.
Pat the beef tenderloin dry with paper towels. This step is important for achieving a good sear. Spread the garlic herb rub evenly all over the tenderloin.
Transfer the seasoned tenderloin to a roasting pan or oven-safe skillet. Insert an oven-safe meat thermometer into the thickest part of the tenderloin.
Roast in the preheated oven. For medium doneness, cook for 28 to 30 minutes, removing it when the internal temperature reaches 130 to 135˚F. Allowing for carryover cooking will get the final temperature to 138 to 140˚F.
Once done, remove from the oven and transfer the tenderloin to a cutting board. Tent it loosely with foil and let it rest for 10 minutes. Resting is crucial for allowing the juices to redistribute, keeping the meat moist and tender.
Slice the tenderloin into 1/2-inch thick slices and serve immediately. Display the slices beautifully on a platter to wow your guests!
