Slow Roasted Leg Of Lamb

The rotisserie is possibly one of the best grilling accessories you can have. Cooking a Slow Roasted Leg of Lamb on the Rotisserie makes for one succulent meal indeed. Savory spices, roasted garlic oil, and a little patience go a long way to making this family dinner an enjoyable one.


  • 1 boneless leg of lamb, 1.5+ lbs
  • 3 tbsp of roasted garlic oil
  • 1 tbsp of thyme
  • 1 tbsp of fennel seeds
  • 1 tsp of rosemary
  • 1/2 tbsp of peppercorns
  • 2 tsp of coarse salt
  • 2 tsp of sage
  • 1 tsp of onion powder
  • 2 cups of beef/lamb broth, red wine, beer, or water

PRO TIP: Remove the grids and sear plates, place Napoleon's Cast Iron Charcoal and Smoker Tray on the burners and use some lump charcoal and wood chips to give your lamb that delicious charcoal flavor.

Original Recipe Found Here:


  1. Preheat your rear burner to high, about 450°F or so.
  2. In a small, dry, frying pan, toast the thyme, fennel, rosemary, and peppercorns until they are fragrant. This will take about 3 minutes over medium-low heat. Use a mortar and pestle to grind up the spices a little before adding the salt, sage, and onion powder, and crushing it up a little more.
  3. Slice the fat on the leg of lamb in a crosshatch pattern. Brush the lamb all over with the roasted garlic oil, then sprinkle the seasonings on, covering every inch, and pressing it into the slices in the fat.
  4. Load up and balance your rotisserie. For some pointers on doing this, check out our video on using your rotisserie. Place the rotisserie on the grill and turn on the motor. Place a drip tray, filled with 2 cups of liquid under the rotating lamb.
  5. Rotisserie the lamb for 10 to 15 minutes on high, or until a lovely crust forms. Turn the grill down, you’re aiming for a temperature of about 350°F, and continue to cook for up to 2 hours, or until an instant-read thermometer says 145°F for medium rare.
  6. Use Napoleon’s PRO Heat Resistant Gloves, to remove the lamb from the grill. Remove the spit rod and forks from the roast before allowing it to rest. You don’t want residual heat to continue cooking the lamb.
  7. To Make Gravy: Use the liquid in the drip tray, alongside any liquid from making vegetables to make gravy. Add ¼ cup of butter to a saucepan. Melt it over low heat and add ¼ cup of flour. Cook for 2 minutes before slowly adding the liquid from the drip tray, vegetable water, and any juices from the resting lamb. With every small addition – ¼ cup of liquid or so – whisk thoroughly. Stop adding liquid when you have reached a thick sauce that coats a spoon but is still runny. If you have added too much liquid, allow the gravy to simmer until thickened a little.
  8. Slice the lamb and serve with your favorite veggies, potatoes, and gravy.

Delicious Smoked Flavor

This Slow Roasted Leg Of Lamb recipe is a great meal that is relatively easy to make, and will be loved by friends and family for a great meal.