Chef Jeremy Sewall has a few tips for cooking lamb, a spring favorite on many holiday tables.
Because lamb is expensive, leg roasted low and slow or a humble shoulder cut are good ways to try the meat. “Lamb shoulder could certainly be roasted,” says the restaurateur, “but keep in mind that it is a much leaner cut of meat and would require some low and slow oven love.”
When trimming the outside of a boneless lamb roast, don’t remove all the fat. A bit helps baste the meat during cooking and improves the flavor.
If your boneless lamb is already tied or wrapped in netting, remove it so you can flatten the meat. On the side that was closest to the bone, trim the meat to an even thickness; this might require cutting thicker pieces to butterfly them or using a meat mallet to pound areas to make them thinner. The lamb should be about an inch or two thick when laid open.
If you don’t have a pan large enough to sear the roast on the stove top, brown it in the oven for 5 to 7 minutes at 500 degrees or slide it under the broiler, turning often and watching it carefully. Remove the roast while the oven cools. Return it to the oven when the temperature resets to 250 degrees.
Sewall likes to serve lamb medium to medium-rare. (“If it’s too rare, it becomes chewy and stringy.”) To achieve that, cooking time can fluctuate significantly, depending on the shape of the roast. Thicker meat will require more cooking time. Use an instant-read meat thermometer to reach an internal temperature of 125-130 degrees for medium-rare, 140 degrees for medium. The lamb should rest in a warm place for 20 minutes before slicing.