Beef Tenderloin Recipe

Bring to room temperature

Remove the beef tenderloin from the refrigerator 45–60 minutes before cooking so it comes to room temperature. Pat dry with paper towels.

Preheat oven and season

Preheat oven to 425°F (220°C). Rub the tenderloin all over with olive oil. Combine kosher salt, black pepper, and garlic powder and season the meat evenly. Tuck thyme sprigs alongside or lay on top of the roast.

Sear the tenderloin

Heat a large ovenproof skillet or roasting pan over high heat until smoking. Add 2 tablespoons unsalted butter and swirl. Sear the tenderloin on all sides (including ends) until deeply browned, about 2–3 minutes per side.

Roast to temperature

Transfer the skillet to the preheated oven. Roast until an instant-read thermometer inserted into the thickest part reads: 120°F (49°C) for rare, 125°F (52°C) for medium-rare, or 135°F (57°C) for medium. For medium-rare with a 3–4 lb roast plan on ~20–30 minutes; a 6 lb roast may take 35–45 minutes. Start checking temperature at 20 minutes.

Rest and finish

Remove the roast from the oven and add remaining 2 tablespoons butter on top; tent loosely with foil and rest 15–20 minutes. During resting, carryover cooking will raise internal temperature about 5–7°F. Slice into 1-inch medallions and sprinkle with coarse finishing salt if using. Reserve pan juices for au jus or sauce.

Prepare potatoes

Place peeled, cubed potatoes in a large pot and cover with cold water by 1 inch. Add 1 teaspoon salt. Bring to a boil over high heat, then reduce to a simmer and cook until the potatoes are fork-tender, about 12–15 minutes depending on cube size.

Warm dairy

While potatoes cook, combine whole milk and 6 tablespoons butter in a small saucepan and warm gently over low heat until butter melts and mixture is warm (do not boil). If using cream cheese, allow it to come to room temperature or microwave gently to soften.

Drain and mash

Drain potatoes thoroughly in a colander for 1–2 minutes to remove excess water. Return potatoes to the hot pot on the warm burner for 30–60 seconds to steam-dry.

Finish mash

Using a potato ricer or masher, mash the potatoes to desired texture. Stir in the warmed milk-butter mixture, sour cream, and softened cream cheese (if using) until smooth and creamy. Season with remaining 1/2 teaspoon salt and 1/2 teaspoon freshly ground black pepper. Adjust seasoning to taste.

Garnish and keep warm

Transfer mashed potatoes to a warmed serving container. Dot with an extra tablespoon of butter if desired and sprinkle chopped chives on top. Keep warm until plating.

Reheat any reserved pan juices or prepare a simple au jus by deglazing the roasting pan with 1 cup beef stock and 1/2 cup red wine over medium heat, scraping browned bits, then reduce slightly and season to taste. Strain if desired.

Plate by spooning a generous portion (about 1 cup) of sour cream mashed potatoes onto each plate. Place 3–4 slices (about 6–8 oz per serving depending on desired portion) of sliced beef tenderloin beside the potatoes. Spoon warm au jus over the beef or serve on the side. Finish with a sprinkle of chopped chives and coarse finishing salt on the beef, if desired.

Serve immediately while beef and potatoes are hot.