Smoked (or Grilled) Leg of Lamb Recipe

Marinated leg-of-lamb is not only delicious, it's surprisingly affordable for weekday meals. Buy one and turn it into 2 or 3 meals on the grill or smoker.

I love lamb. Whenever I see it on a restaurant menu, you can bet I'll be ordering it (unless there is also duck on the menu). The problem with cooking it at home is that loin chops or rack of lamb are pretty pricey, and leg of lamb comes in huge 5-6 lb chunks that are too much for the average family.

For me, buying a leg of lamb and cutting it up into 2 or 3 meals is the right answer. With a good marinade, leg of lamb is as good or better than lamb chops, at a lower price. It's also about half the price of a good ribeye steak.

Put about 20 minutes of work into marinating the whole leg, then split it into 2 or 2 pieces and freeze the extra for future meals. Cooking smaller portions has several benefits:

  • Tastes better!  More surface area marinated (vs. rolled up leg), more surface seared on grill.
  • Cooks faster!  Thinner, more like cooking a steak than a whole leg.
  • Meals 2 and 3 are easier! The meat is pre-marinated.

The recipe below is for 1/2 of leg of lamb. The marinade is adapted from Guy Fieri's excellent Leg-O-Lamb with Rosemary-Au-Jus on Food Network. The rest of the instructions are intended for a dedicated smoker, since "anything that is great on a grill is even better on a smoker". If you don't have a smoker, here are some suggestions:

  • To grill it, I suggest setting up one side of your grill as indirect heat (flame turned off or very low), and cooking it until it reaches 110 degrees. Then finish it by searing on the hot side of the grill. These are thick pieces of meat, so cooking it indirectly will get the inside cooked more evenly without burning the living heck out of the outside. 
  • To bake it, refer to Guy's article above. 

This is the way I like them - about 135 degrees. Cook them longer if you prefer, but above 150 you are out of the sweet zone. remember that they rise about 5 degrees during resting.

TOTAL TIME: 14 hr

  • Prep:      20 min
  • Marinate: 12 hr
  • Smoke:   1 hr 20 min
  • Grill:        15 min
  • Rest:        5 min

YIELD:   5 servings

LEVEL:  Medium

INGREDIENTS

  • 1/2 of a 5-6 pound boneless leg of lamb, butterflied (cook half, freeze half)
  • Rosemary Au Jus marinade (for the entire leg):
    • 1/3 cup fresh rosemary leaves (or about 2 tablespoons dried rosemary)
    • 1/3 cup chopped fresh garlic (or about 2 tablespoons garlic powder)
    • 1/2 cup balsamic vinegar
    • 1/3 cup soy sauce
    • 2 tablespoons course ground black pepper
    • 2 lemons, zested and juiced - about 1/2 cup lemon juice

DIRECTIONS

Butterfly a leg of lamb. Remove the bone if it has one. Try to cut it so that the meat is uniform thickness so that it will cook to a consistent temperature throughout. Remove any excessive fat (there is usually a fat cap on one side).

Marinate it using the Rosemary Au Jus marinade. Make the marinade by combining all ingredients in a plastic ziploc bag. Add the lamb and throw it in the fridge overnight (12 - 24 hours).

Freeze half of it. Seal in a ziploc with the air squeezed out, then double-bag it and freeze.

SHOPPING TIPS

  • Costco has good prices on Australian lamb.
  • Boneless legs of lamb average 5 - 6 pounds. You can marinade once, then split it in half or in thirds. Cook one and freeze the others for future meals without the marinade lead-time.

Smoke the other half of it at 225 degrees until the lamb reaches 115 degrees internal temperature. See my notes on food thermometers in Cooking Tools if you don't have one. It took about 1 hour 20 minutes for my two pieces totalling 2.5 lbs to go from 41 degrees to 115 degrees.

Sear the outside and finish cooking at medium high heat on a traditional grill (or crank your smoker up to 400 if it will go that high). Take it off the grill at about 130-135 degrees internal temperature if you like it very pink. Let it rest for five minutes, then slice.


More Photos

Our Costco has been selling leg of lamb for months at $5 per pound - half the price of Ribeye.

A lot of it about the same thickness when you unwrap it. I cut the thickest part off, and the result is pretty good.

On its side, what was the thick part is now about the same thickness as the rest. This is what you want.

Marinate it in a plastic bag with the air squeezed out. Place it a container in the refrigerator overnight.

After marinating, I split the leg in half - cooked the two pieces on the right, and froze the rest for an easy meal in the future.

On the smoker at 225 degrees. it took them about 1 hour 20 minutes to heat from 41 to 115 degrees. I had removed them from the refrigerator (34 degrees) about 20 minutes before cooking.

When they reached 115 degrees internal on the smoker, I moved them to my traditional grill at medium high heat to sear them.  It took a good 15 minutes for them to reach 130 degrees internal.

Straight off the grill - looking good! Let them rest for 5 minutes before carving. If they are large, like the one on the left, carve the whole thing to keep it from cooking further.

This was pulled off the grill at 130 degrees, then rose to 135 after resting for 5 minutes.

This is from the piece that i Froze, after marinating, for another 3-4 weeks after the first cook. I didn't notice any difference from having frozen the lamb after marinating.