Knuckle: The Sirloin Tip for Roasts, Kebabs, and Thin Steaks

The knuckle, better known at the counter as the sirloin tip, is a lean, versatile, affordable cut that quietly does a lot of work. It roasts, it cubes for kebabs, it slices thin for sandwiches and stir-fries, and it grinds for lean burgers. Like the rest of the round, it is lean and best handled gently, but it is a genuine bargain and more tender than its neighbors. For everyday beef that stretches across many dishes, the knuckle is worth knowing.

Where it comes from

The knuckle sits at the front of the beef round, near the sirloin, which is why it is often sold as sirloin tip even though it is technically part of the round. It is a lean group of muscles, a little more tender than the deeper round cuts because it does slightly less work. It is sold as a sirloin tip roast, as thin sandwich or sandwich steaks, and cubed for kebabs and stew.

What it tastes like

Cleanly beefy and lean, a touch more tender than the eye or bottom round, with a firm texture and honest flavor. It lacks the marbling of the rib and loin, so its appeal is in gentle roasts and thin slices rather than rich steaks. Cooked to medium-rare and sliced thin against the grain, it is tender enough and full of straightforward beef flavor, which makes it a reliable everyday cut.

How to cook a knuckle

Gently for roasts, fast for kebabs, and never past medium-rare for either. Roast a sirloin tip low and slow to an even 130F to 135F, rest it, and slice it thin against the grain for roast beef. Cube it for kebabs and grill them fast over high heat, pulling at medium-rare so they stay juicy. Thin sandwich steaks cook in seconds on a hot griddle for cheesesteaks. Tougher pieces braise into a lean stew. We roast, grill, and braise in metal or cast iron, never plastic. Our roasting, grilling, and braising guides all apply.

As with all the round cuts, keep it rosy and slice it thin against the grain. A marinade helps for kebabs and grilled pieces, adding flavor and a little tenderness to a lean cut.

Classic dishes to make

A sirloin tip roast, cooked rosy and sliced thin, makes good roast beef for sandwiches and dinners. Cubed, the knuckle is a favorite for beef kebabs and skewers. Thin sandwich steaks become cheesesteaks and hot beef sandwiches, and thin slices go into stir-fries and beef and broccoli. Ground, it makes lean burgers and meat sauce. It is the flexible, budget everyday cut.

Common mistakes

Overcooking dries the lean knuckle, so pull roasts and kebabs at medium-rare. Slicing thick or with the grain leaves it chewy, so slice thin across it. Skipping a marinade on kebabs misses a chance to season and tenderize. And treating it like a marbled steak, searing it to well done, leaves it tough, so roast, grill fast, or braise instead.

How to buy it

Look for firm, bright red, lean meat, sold as knuckle or sirloin tip. A sirloin tip roast is the pick for roast beef, cubes for kebabs, and thin steaks for sandwiches. It is affordable and versatile, good value for feeding many. Grass-fed beef suits its gentle methods. Ask your butcher or use our Find a Farmer directory.

Good substitutes

The top round is a similar lean round cut for roasts and London broil. The eye round is leaner and neater for roast beef. Top sirloin is a more tender, pricier option for kebabs and grilling. For thin sandwich steaks, ribeye or top round also work depending on budget.

Storage and leftovers

Keep raw knuckle well wrapped in the coldest part of the fridge and cook within three to five days, or freeze for several months. Roasted knuckle keeps three to four days and is best sliced thin and served cold, since reheating dries this lean cut. It makes good sandwiches and salads. Marinated kebab cubes can be prepped a day ahead.

Nutrition

The knuckle is lean and high in protein, with iron, zinc, and B vitamins and modest fat. That leanness makes it a good everyday choice for those watching fat, as long as you cook it gently to keep it tender. A marinade or light sauce adds flavor without much fat, and thin slicing or cubing stretches it across a plate of vegetables and grains.

Frequently asked questions

Is the knuckle the same as sirloin tip?

Yes, they are the same cut. It sits near the sirloin but is part of the round, which is why it carries both names.

What is the knuckle best for?

Sirloin tip roasts, kebabs, thin sandwich steaks, stir-fries, and lean ground beef. It is a versatile, budget-friendly cut.

What temperature should a sirloin tip roast be?

Roast it to 130F to 135F for medium-rare and no further, then rest and slice thin. Past medium it dries out.

Is the knuckle tender?

It is a little more tender than the deeper round cuts but still lean, so cook it to medium-rare and slice thin against the grain.

What to serve with it

A sirloin tip roast wants horseradish and roasted potatoes, or bread for sandwiches. Kebabs go with flatbread, a yogurt sauce, and grilled vegetables. Because it is lean and mild, a punchy sauce, marinade, or condiment carries the plate, with something fresh alongside.

A note on kebabs

The knuckle is one of the best value cuts for kebabs, and a little care makes it excellent. Cut the meat into even cubes so they cook at the same rate, and trim any tough silverskin. Because it is lean, a marinade matters more than it would for a fatty cut: an hour or more in oil, acid, and aromatics seasons the cubes and helps keep them juicy. Thread them with a little space between pieces rather than packed tight, so the heat can reach all sides and build a char, and grill them hot and fast, pulling at medium-rare. Overcooked lean kebabs turn dry and chewy, so watch them closely and take them off while they are still rosy in the center.

Learn more

Back to the beef round guide and the Beef Meat Wiki. For the leanest round roast, see the eye round, or find good beef through Find a Farmer.