Preheat your grill to 400°F with direct and indirect heat zones.
Roasted Garlic and Butter Marinated Beef Tenderloin
This Roasted Garlic and Butter Marinated Beef Tenderloin may become your go-to recipe for the holidays and important dinner parties when you want to impress. The herb-seasoned butter with red wine bastes the tenderloin while it slow cooks and a reverse-sear at the end locks in all those juices.
Cut the top third of the garlic bulb completely off. Place the bulb on a piece of aluminum foil. Drizzle with extra-virgin olive oil and sprinkle with salt. Wrap foil tightly around the bulb. Place on the grill over indirect heat on the grill for 35 to 40 minutes.
Meanwhile, bring red wine to a low simmer in a small saucepan. Simmer uncovered until thickened and reduced to 2 tablespoons.
Pat the tenderloin dry with paper towels. Fold the tapered ends of the tenderloin under and secure tightly with twine. Tie twine tightly around the tenderloin in 1 to 1 ½ inch sections, forming a uniform shape to ensure even cooking.
Cream together the butter, roasted garlic, shallot, Worcestershire sauce, Dijon mustard, red wine reduction, rosemary, canola oil, salt and pepper until well combined.
Spread the butter marinade over the entire tenderloin. Cover in plastic wrap and chill in the refrigerator for 1 hour, up to a day.
Let tenderloin come to room temperature while you preheat the grill to 250°F.
Remove the tenderloin from the plastic wrap. Wrap it tightly in aluminum foil to ensure the juices and melted butter will not leak out when rotating on the grill.
Place the tenderloin in a roast and rib rack in the center of your grill. Slow cook until the internal temperature reaches 125-130°F, about 2 to 3 hours. Flip tenderloin every 30 minutes or so, for a flavorful butter-baste. Start checking the internal temperature using an instant-read thermometer at 2 hours.
Remove from grill at 125°F for rare or 130°F for medium rare. Rest the tenderloin at room temperature for 10 minutes.
Increase grill temperature to 450°F.
Carefully remove the tenderloin from the foil, using tweezer tongs or silicone gloves to protect your hands. Reserve the juices that have collected inside the foil.
Sear tenderloin on the grill until the meat is well-browned on all sides, about 1 minute per side.
Transfer tenderloin to a cutting board and rest for 5 minutes. Slice into ½ inch slices and drizzle with reserved cooking juices.