Roast Sirloin

Ingredients

Equipment Needed

• •Heavy low-sided roasting pan, about 13 by 9 inches (33 by 23 cm)
• •Leave-in probe thermometer
• •Instant-read thermometer
• •Large cutting board with a juice groove
• •Long slicing knife and sturdy carving fork

Instructions

1. 1

   Specify the joint

   Ask the butcher for a two-bone section of short-loin sirloin with both the broad upper loin and its smaller undercut, or tenderloin, attached. Have the flat vertebral bones cracked through at their base but left in place, which preserves the joint during roasting and lets a carving knife free the bones afterward. Remove only loose, ragged excess from the flank. The thick fat covering the undercut must stay.

   Butchery names vary between markets. Describe the structure you need rather than relying on the word sirloin alone: two muscles, bone-in, tenderloin attached, protective fat intact.
2. 2

   Season without trimming

   Pat every exposed surface dry, leaving the roast tied if the butcher secured it. Season evenly with the salt and pepper, pressing the seasoning onto the fat as well as the meat. Let the joint stand in a cool kitchen for 45 minutes while the oven heats; this gives the salt time to dissolve and the surface time to dry, but it does not need to become warm at its centre.

3. 3

   Set steady heat

   Heat a conventional oven to 375°F (190°C), with a rack in the lower-middle position. Set the roast bone-side down in a heavy, low-sided roasting pan, with the broad upper loin toward the slightly hotter rear of the oven and the protected undercut toward the door. The bones form a natural rack. Insert a probe into the centre of the upper loin without touching bone. Do not begin with a fierce burst of heat; a dark exterior gained before the two muscles cook evenly defeats the whole preparation.

4. 4

   Roast by temperature

   Roast without disturbing the joint for 60 minutes, then begin checking both muscles with an instant-read thermometer every 10 minutes. For a rosy medium-rare finish, remove the roast when the upper loin reaches 125 to 128°F (52 to 53°C) and the protected undercut is no higher than 132°F (56°C), usually after 75 to 90 minutes. If the fat becomes deeply bronzed before the upper loin reaches 115°F (46°C), cover only that dark patch loosely with foil. If the undercut runs more than 10°F ahead of the upper loin, shield its side as well and turn the broad loin toward the rear of the oven. Ça se rattrape. If the pan residue threatens to blacken, add the hot water to a bare corner of the pan without wetting the roast.

5. 5

   Rest the roast

   Transfer the roast to a large board with a juice groove and leave it uncovered for 25 to 30 minutes. The internal temperature will continue to rise as the heat settles through the joint, while the meat fibres relax enough to hold their juices when cut. If the temperature has already passed your target, move the roast immediately to a cool board and do not cover it; this limits further cooking. Pour off the clear beef fat from the roasting pan, preserving any dark meat juices underneath.

6. 6

   Carve both muscles

   Remove the twine. Run a long knife against the cracked vertebral bones and lift the bone section away in one piece; if the butcher did not crack them, carve each muscle away from the skeleton rather than forcing a household knife through bone. Slice the broad loin across the grain, then cut the tenderloin into slightly thicker medallions. Arrange both on a warmed platter, spoon over the resting juices and the dark juices from the pan, and serve at once. The exterior fat may be left at the edge of each slice or removed at the plate, because its protecting work is now complete. À table!

Chef Tips

• •Order the joint ahead and speak directly with the butcher. A boneless top-sirloin roast is not the same cut: it lacks the attached undercut, its protective covering, and the bones specified by the preparation.
• •The heavy fat is not an obligation to eat every mouthful. It is insulation. Leave it during roasting, then let each diner keep or remove the edge from the carved slice.
• •For diners who need beef cooked to the usual public-health guideline, roast until the broad loin reaches 135 to 138°F (57 to 59°C), then rest until the centre reaches at least 145°F (63°C). The meat will be medium rather than medium-rare, but the fat shield still protects the undercut.
• •Serve the carving juices, not an invented sauce. A firm red Bordeaux from Médoc suits the roast's deep beef flavour, and neither the wine nor the meat needs ornament.
• •Chill leftovers within two hours and keep them well wrapped for up to three days. Slice the meat cold for sandwiches, or warm thick slices very gently with a spoonful of reserved juice so the tenderloin does not dry.

Advance Preparation

• •Order the joint several days ahead so the butcher can leave the undercut and its fat covering intact, crack the vertebral bones correctly, and tie the roast without compressing it.
• •The roast may be salted and left uncovered in the refrigerator for 12 to 24 hours. This dries the surface for stronger browning and seasons the meat more evenly; use the same quantity of salt, then add only the pepper before roasting.
• •Warm the serving platter during the roast's resting time. Have the carving knife sharpened before dinner, because the cracked bones make carving possible, but a dull blade still makes a ragged business of it.

Frequently Asked Questions

Nutrition Information

1 serving (about 320g)