Start by removing the netting from the boneless leg of lamb and place it on a rack over a sheet tray. Be sure to keep the netting.
Season the lamb on both sides with salt and pepper and place it uncovered on the rack and sheet tray for 24-48 hours in the refrigerator.
About 30 minutes before the lamb is ready to be cooked, preheat the smoker or oven to 225°.
Next, mix the oil with thyme, rosemary, parsley, 5 roasted garlic cloves, salt, and pepper until combined. Set it to the side.
Remove the lamb and place it fat side down on the rack. Using a sharp knife, make 1” wide and deep incisions in 20-25 places about ½” to 1” inch apart from each other.
Stuff a roasted garlic clove in each slit until all the holes are filled.
Next, pour about a 1/3 of the herb oil mixture over the inside of the lamb and spread it out using a spoon, brush, or your hands. Fold the boneless leg of lamb back over and place the netting around it again.
Use another 1/3 of the herb oil mixture over the outside of the lamb and spread it all around using a spoon, rush, or your hands, completely covering it.
Place the lamb on a top rack in the smoker with a drip pan underneath. It’s important to use a drip pan. If you are cooking in the oven, place the lamb directly in a 13x9 pan and place it on the middle rack in the oven. Smoke or cook until it reaches an internal temperature of 100° F, which takes about 2 hours.
Next, turn the heat up to 500° and cook it until it reaches 125° internally for medium-rare, 135° for medium, 145° F for medium-well, or 155° for well.
Remove it from the smoker or oven and place on a cutting board to rest for 15 to 20 minutes.
Optional Pan Sauce: If you want to make the pan sauce, take the drippings from the pan and place them in the freezer to chill quickly.
For the sauce, add 1 to 2 tablespoons of olive oil to a medium-sized sauce pot over medium heat. Add in shallots and sauté until lightly browned, which takes about 2 to 3 minutes.
Deglaze with the wine turn the heat to high, and cook until there are 2 to 3 tablespoons of the liquid left.
Pour in the beef stock and cook until about 1 cup left, which takes about 10 minutes. Finish by whisking in the chilled pan drippings, optional minced fresh parsley, salt, and pepper.
Remove the netting from the lamb and thinly slice it. Garnish with remaining 1/3 of herb oil and optional pan sauce.
Notes
Make-Ahead: This recipe is meant to be eaten as soon as it is done cooking and resting. However, you can make it up to 1 hour ahead of time and keep it warm at low temperatures in the oven, at around 225° F, before serving it.How to Store: Place covered in the refrigerator for up to 5 days. Cover and freeze for up to 3 months. Thaw in the refrigerator for 1 day before reheating.How to Reheat: Place the desired amount of meat in a medium-sized pan, add ¼ cup of beef stock or leftover sauce, and heat at 350° for 8-12 minutes or until hot. Any dry red wine will work for the sauce.You do not need to make the red wine brown sauce for this recipe.Try cooking this on the smoker or in the oven like a smoked pork shoulder to where the meat easily shreds apart. To do this, cook it at 225° until it reaches 170° F internally and then wrap it in foil or butcher’s paper. Cook wrapped at 225° F until it reaches 204° F internally. Rest it for 25-30 minutes before unwrapping and shredding.The pan sauce at the end is completely optional.You can make this in the oven using the same temperatures. However, place the lamb on a rack inside of a pan. Do not place the leg of lamb directly on an oven rack. Use a pan.