This low-and-slow method of roasting your prized beef tenderloin produces perfectly cooked slices of tender juicy meat. For the least waste, trim the tenderloin yourself. The goal is to trim away as little as possible, but remove all of the silverskin, a tough sinewy length of connective tissue. The meat will be tied to keep any muscle separation intact. Discard the silverskin, but save the rest of the trimmings to make Au Jus, if you like.
3 pounds beef tenderloin
2 tsp kosher salt
1 tsp coarsely ground pepper
8 Tbsp unsalted butter, softened, divided
1 small shallot, minced
1 Tbsp fresh parsley, minced
1 tsp minced garlic
1/4 tsp salt
1/4 tsp pepper
1 Tbsp vegetable oil
1. If your tenderloin has a tapered end, tuck it under to give the meat a more even shape. Use butcher’s twine to tie the roast crosswise at 1 1/2 -inch intervals.
2. An hour before roasting, sprinkle the beef evenly with the kosher salt and let come to room temperature.
3. Preheat the oven to 300°. Place a wire rack over a foil lined rimmed baking sheet.
4. When ready to roast, pat the beef dry with paper towels. Sprinkle the roast evenly with pepper, then spread 3 Tbsp of the softened butter over the entire surface.
5. Insert a probe-type thermometer into the thickest end of the roast, not touching fat. Place the roast on the wire rack and place the baking sheet on the center rack of the preheated oven.
6. While the beef is roasting, make a compound butter. In a small bowl, combine the remaining 5 Tbsp of softened butter with all the remaining ingredients, except the oil, and set aside.
7. Roast the beef until the thermometer reads 125° for medium-rare or 135° for medium, flipping the meat after 25 minutes. Remove the probe.
8. In a very large skillet, heat the oil until it just begins to smoke. Place the roast in the skillet and sear until well browned on all sides. Use tongs to hold the roast to brown the ends.
9. Transfer the roast to a cutting board and top with half the compound butter. Let rest for 15 to 20 minutes.
10. Remove the twine and cut the tenderloin crosswise into 1/2-inch slices. Top each slice with a little more of the compound butter to serve.