Leg Of Lamb – Honey, Mustard, Garlic & Rosemary Marinated

Summary

Buy a 5-7 pound bone-in, semi-boneless or boneless leg of lamb.
Marinate overnight in honey, Dijon mustard, garlic & rosemary mixture.
Pat meat dry, brushing off loose pieces of marinade. Sprinkle with kosher salt and lemon pepper to taste.
Cook at 225-250°F to an internal temperature of 130°F for medium-rare or 140°F for medium.
Place cooking grate directly over hot coals. Sear meat on all four sides, approximately 2 minutes per side.
Tent with foil and let rest for 15 minutes before slicing.

Lamb is not the most popular of barbecued meats, but it can be delicious when marinated and smoked to perfection in the Weber Bullet. Garlic and rosemary are commonly used with lamb, but using them with honey and Dijon mustard as a marinade is a nice twist that tastes great.

Here’s a description and photos of how I cooked this leg of lamb on May 23, 2009.

Select The Lamb

Choose a leg of lamb weighing 5-7 pounds, either bone-in, semi-boneless or boneless. The leg shown here is a Niman Ranch semi-boneless leg weighing 6 pounds, 11 ounces.

Semi-boneless leg of lamb before marinating

The advantage of semi-boneless or boneless is that the leg is easier to carve after cooking. Unlike a bone-in leg, a semi-boneless or boneless leg will have to be tied with kitchen twine or netted as shown here.

Marinate The Lamb

Prepare the marinade using these ingredients:

Marinade For Leg of Lamb

1/4 cup honey
2 Tablespoons Dijon mustard
2 Tablespoons chopped fresh rosemary
1 teaspoon freshly ground black pepper
1 teaspoon lemon zest
3 cloves garlic, minced

Combine the ingredients and mix well.

Apply the marinade to the lamb, place in a Ziploc bag and refrigerate overnight.

This photo shows how the lamb looks after marinating.

Shortly before cooking, pat the lamb dry with paper towels and brush off any loose pieces of the marinade. Apply kosher salt and lemon pepper to taste, as shown below.

Close-up of leg of lamb sprinkled with kosher salt and lemon pepper

Wrap the exposed bone with aluminum foil to prevent it from burning during cooking.

Fire The WSM

Fire-up the Weber Bullet using the Minion Method—fill the charcoal chamber about 1/2 full with unlit Kingsford Charcoal Briquets and then spread about 30 hot coals over the unlit ones.

Smoke The Lamb

Place 3 small chunks of dry oak wood on the hot coals. Assemble the cooker with the water pan in place and fill it with water.

Put the leg of lamb on the top cooking grate and cover with the lid.

Leg of lamb goes onto the top grate of the WSM

Set the top vent to 100% open and leave it that way throughout the entire cooking process. Start with all 3 bottom vents 100% open. As the cooker approaches 225°F, begin to partially close all 3 bottom vents to maintain 225-250°F. Adjust the bottom vents as needed to maintain this temperature range throughout the cooking process.

Start checking the internal temperature of the lamb about 90 minutes into the cooking process with an instant-read thermometer. Cook to an internal temperature of 130°F for medium-rare, 140°F for medium. Check the temperature in several locations and average the results to determine doneness.

Leg of lamb cooked and ready for searing

There is no need to turn or baste the lamb during cooking.

Here’s how the cooker temperatures and vent settings went during my cook:

Time	Lid Temp	Meat Temp	Vent 1 %	Vent 2 %	Vent 3 %
12:30 pm	–	–	100	100	100
12:45 pm	232	–	100	100	100
12:55 pm	246	–	50	50	50
1:30 pm	255	–	50	50	50
2:00 pm	261	86	33	33	33
3:00 pm	250	127	33	33	33
3:30 pm	249	135-140	33	33	33

Note that the vent percentages represent the way I set the vents at the time indicated.

Sear The Lamb

Searing the lamb at the end of cooking, also known as reverse searing, adds great flavor and color to the meat.

Remove the top cooking grate from the cooker and set it aside. Lift off the middle cooking section and set it aside, being careful to not spill the hot contents of the water pan. Use tongs to evenly spread out the hot coals in the charcoal chamber, if necessary.

Place the cooking grate directly on top of the charcoal chamber. Sear the leg of lamb on all four sides, approximately 2 minutes per side or until browned to your liking.

Rest The Lamb Then Carve

Remove the lamb from the cooker to a platter. Tent with foil and let rest for 15 minutes before slicing.

Carving a semi-boneless or boneless leg of lamb is simple: Remove the butcher’s twine or netting and cut across the width of the leg into 1/4″ – 1/2″ slices.

To carve a bone-in leg of lamb, cut a few slices parallel to the bone from the less meaty side of the leg to create a flat area (the less meaty side would be the backside of the leg here). Turn the leg onto the flat area and start cutting 1/4″ – 1/2″ slices across the width of the leg. At some point you will hit bone…keep slicing to the end of the leg, then release the slices from the bone by cutting under the slices down the length of the bone. You will find several illustrated examples of this carving method on the Web by searching for carving a leg of lamb.

I recorded in my cooking log that this leg of lamb had a decent smoke ring—about 1/4″ wide—and was very moist and tender, with moderate smoky aroma and flavor. The marinade contributed nicely to the flavor without being overpowering.