Preparing a Leg of Lamb
Leg of Lamb 101
1. Trim the Shank Bone
For the cleanest-looking presentation, trim 1 1/2 inches of flesh from the shank bone with a sharp paring knife. (Your butcher may be willing to do this for you.)
2. Remove Fell (If Necessary)
The fell is a thin outer layer of fat that you may find if you buy an untrimmed leg from a butcher. It's very tough, so it's important to remove all of it. A long knife with a sharp thin blade is the best tool for the job.
3. Trim the Fat
Trim the excess fat that lies beneath the fell, but leave enough to enrich the meat and gravy. It also crisps up nicely when broiled, which helps give the carved slices great texture. Use shears to trim the fat pads around the hip, or large end.
4. Slash the Meat
Make incisions 1 inch long and 1/2 inch deep all over the leg; they'll allow the aromatic rub to penetrate the meat more easily. Roughening the surface in this way also results in a crisper, more flavorful crust after broiling.
5. Slather on the Rub
Stir together salt, pepper, garlic, rosemary, mustard, and oil in a small bowl until it forms a wet paste. Spread rub evenly over lamb, working it into the incisions. Let lamb sit at room temperature, about 30 minutes. Meanwhile, preheat oven to 425 degrees.
6. Now You're Cooking
Transfer lamb, fat side up, to a large roasting pan fitted with a rack, and add broth. Roast lamb 20 minutes. Reduce temperature to 325 degrees, and roast until a thermometer inserted into thickest part of flesh near the bone reaches 130 degrees to 135 degrees (medium-rare), about 55 minutes. Increase temperature to broil; broil until surface sizzles and becomes brown and crisp, about 5 minutes. Transfer lamb to a platter or carving board; let rest at least 20 minutes before carving.
Then You're Carving
After the meat has rested, it's ready to carve.