Sirloin Of Aged British Beef Recipe

Bring to room temperature

Remove the sirloin from the refrigerator 60 to 90 minutes before cooking (longer if very thick) so it comes to near room temperature—this promotes even cooking.

Pat dry and season

Pat the beef thoroughly dry with paper towels. Rub both sides and the edges evenly with 2 tablespoons kosher salt and 2 teaspoons freshly ground black pepper. Press the crushed garlic cloves and thyme sprigs gently onto the surface so they adhere; you can tuck a couple of thyme sprigs under the butchers' twine or against the bone for aromatic flavor.

Preheat oven and pan

Preheat oven to 200°C (390°F). Place a heavy ovenproof skillet (cast iron preferred) on the stovetop over medium-high heat for 4–5 minutes until smoking hot.

Sear the sirloin

Add 2 tablespoons neutral oil to the hot pan, swirl to coat. Place the sirloin fat-side down first (if it has a fat cap) and sear without moving for 2–3 minutes until a deep brown crust forms. Turn and sear each side and the edges for about 2 minutes per side until an even caramelized crust develops (total sear time ~8–10 minutes).

Add butter and aromatics

Reduce heat to medium. Add 75 g unsalted butter to the pan along with the reserved crushed garlic and remaining thyme. Tilt the pan slightly and baste the beef continuously with the melted butter for 30–60 seconds to build flavor and color.

Roast to desired doneness

Transfer the pan to the preheated oven. Roast until internal temperature reaches your target: 52°C (125°F) for rare, 57°C (135°F) for medium-rare, or 63°C (145°F) for medium. For a 1 kg sirloin, expect roughly 12–20 minutes in the oven depending on thickness and target doneness—start checking with an instant-read thermometer at 10 minutes.

Rest the beef

Remove sirloin from the oven and transfer to a carving board. Tent loosely with foil and rest for 15–20 minutes. Resting allows juices to redistribute and carryover cooking to finish. Reserve pan and any juices for the pan sauce.

Deglaze the pan

Place the skillet over medium heat. If the pan is very fatty, spoon off all but ~1 tablespoon of fat. Add the minced shallot and cook 1–2 minutes until softened but not browned. Pour in 120 ml dry red wine, scraping up browned bits from the pan with a wooden spoon. Reduce wine by about half (2–4 minutes).

Reduce with stock

Add 200 ml beef stock and simmer until the sauce lightly coats the back of a spoon and is reduced by about one-third (5–8 minutes). Taste and adjust seasoning with salt and pepper if needed.

Finish the sauce

Remove the pan from heat and swirl in 25 g cold cubed butter a few pieces at a time to emulsify and gloss the sauce. Stir in 1 tablespoon chopped fresh parsley if using. Strain the sauce through a fine sieve into a small jug if you prefer a smooth sauce.

Serve

Carve the rested sirloin against the grain into 5–7 mm slices. Spoon warm pan sauce over the slices or serve on the side.