Lamb rumps aren't tough like most other meat taken from the hind end of an animal, so they don't need to be tenderized or cooked low and slow. Lamb rumps, the British nomenclature for the meat between the tenderloin and leg, correspond with sirloins in the American market. As such, this versatile cut responds well to both short bursts of heat and long braising. Whether you cook it for a few minutes on the grill or a few hours in the oven, you get the same tenderness every time.
Seared and Roasted
Take the lamb rump out about 30 minutes before you want to start cooking and let it sit at room temperature. Pat the rump dry with paper towels and season it to taste with kosher salt and freshly ground black pepper.
Heat the oven to 350 degrees Fahrenheit. Heat a couple tablespoons of oil or oil and butter on the stove in an oven-safe pan. Use medium-high heat on the stove.
Sear the lamb rump skin-side down until the skin starts to curl at the edges, about 2 to 3 minutes. Turn the lamb rump and sear another 2 to 3 minutes.
Transfer the pan to the oven. Roast the rump for 10 minutes for medium-rare and 12 minutes for medium. Take the pan from the oven and set the rump on a plate to rest for 5 or 10 minutes.
Drain the all the fat from the pan except about 1 tablespoon and return it to the stove if you want to make a quick pan sauce. Saute minced aromatics, such as shallots and garlic, with a tablespoon or so of flour until browned.
Deglaze the pan with a scant pouring of dry wine and add about a cup or so of stock. Bring the stock to a boil and cook until thickened, about 5 minutes.
Slice the lamb rump across the grain into 1/4- to 1/2-inch-thick slices. Spoon the pan sauce over the sliced lamb and serve.
Slice the lamb rump into 3/4- to 1-inch cubes and season them to taste with kosher salt and freshly ground black pepper. Dredge the lamb cubes in flour.
Set the oven to 450 F. Heat a few tablespoons of oil in a Dutch oven on the stove over medium heat. Sear the lamb in batches until browned all over, about 5 minutes per batch, then transfer it to a plate.
Saute a mirepoix, or chopped onions, carrots and celery, with some garlic until lightly colored, about 5 minutes. Add a little more oil if needed.
Add 2 or 3 tablespoons of all-purpose flour to the mix and cook until you smell a nutty aroma. Add 1 part dry red wine and 2 parts stock or water to the Dutch oven. You need about 2 cups of liquid total for each lamb rump.
Add aromatics, such as bay leaves, thyme sprigs and black peppercorns, and return the lamb to the Dutch oven. Cover the Dutch oven with the lid and bring it to a simmer. Place the Dutch oven in the conventional oven.
Add a starch, such as diced parsnips or potatoes, to the stew after 30 minutes in the oven, if desired.
Stew the lamb rump until the starchy vegetables cook through. Serve immediately or store up to 2 days in the refrigerator.
Marinate the rump for a couple hours before you want to grill it, if desired. You don't have to worry about tenderizing the lamb, just focus on flavor. Yogurt-based marinades always work with lamb.
Set the lamb rump out about 15 minutes before you set up the grill. Wipe off the excess marinade.
Set up your grill for moderately high direct heat. If you have a gas grill, set the burners to medium-high. If you have charcoal, use an even layer of charcoal in the charcoal tray.
Season the lamb rump to taste and coat it with oil. Lay the rump on the grill.
Grill lamb rump for about 5 minutes on each side for medium-rare, and 12 minutes on each side for medium. Transfer the lamb to a carving board.
Let lamb rump rest about 5 minutes before slicing. Slice the lamb rump across the grain into 1/4- to 1/2-inch-thick slices and serve.