Smoking a leg of lamb is one of the best ways to highlight its rich flavor while keeping the meat tender and juicy. Cooking the roast low and slow allows the smoke to complement the lamb’s natural flavor without overpowering it. Keeping the smoker between 225–250°F helps develop clean smoke flavor while preventing overcooking.

For this cook, we ran our smoker at 250°F and relied on our RFX Wireless Probe to monitor the internal temperature of the lamb throughout the cook. Maintaining a steady pit temperature is just as important, which is where Billows BBQ Control Fan helps keep the smoker stable without constant adjustments.

We've taken inspiration for this cook from Susie Bulloch of Hey Grill Hey. Susie is one of the top voices in BBQ today, and her thermal tips for cooking a sumptuous leg of lamb helped steer us in the right direction.

Building Flavor: Dijon and Fresh Herbs

To create a bold crust, we started with a thin layer of Dijon mustard as a binder. Mustard helps the seasoning adhere to the meat while adding subtle acidity that balances the lamb’s richness.

Next, we built a fresh herb mixture using:

• Lemon
• Garlic
• Shallots
• Fresh mint
• Fresh sage
• Kosher salt
• Black pepper

Smoking the Lamb at 250°F

Preheat your smoker to 250°F. Once the lamb is seasoned, place it on the smoker grate and insert the RFX Wireless probe into the thickest part of the roast.

Tracking the cook with a wireless probe allows you to monitor the temperature in real time without opening the smoker and losing heat. Pairing RFX Wireless with Billows helps maintain steady airflow and temperature, which is critical for long cooks and consistent results.

Cook the lamb until the internal temperature reaches 125–128°F.

Verifying Doneness

Before removing the roast, verify the internal temperature with an instant-read thermometer like Thermapen ONE. Checking multiple spots ensures the lamb has reached the correct temperature throughout the roast.

After resting for about 10–15 minutes, carryover cooking will bring the lamb into the ideal 130–135°F range for medium rare. 

Why Temperature Control Matters

Lamb can move from perfectly tender to overcooked quickly. Using tools like RFX to track the cook, Billows to stabilize pit temperature, and Thermapen ONE to verify doneness removes the guesswork and ensures consistent results.

The final roast delivers everything you want from smoked leg of lamb:

• A deep garlic herb crust

• Light smoke flavor

• Tender medium-rare slices

With the right temperature control and a simple herb crust, smoked lamb becomes one of the most impressive roasts you can cook on a smoker.

Bone-in or boneless leg of lamb?

Whether to get bone-in or boneless leg of lamb is a matter of taste. But for this application, where we're cooking slowly in a smoker, we prefer a boneless leg. They're usually easier to find and easier to carve. Plus, the ability to season inside the leg—where the bone used to be—allows you to pack more flavor into a large cut of meat.

Whether you're making a lamb roast for an Easter feast or just to celebrate the coming of spring (or just because you want something tasty any time of the year), smoking it is a great way to go. The smoky flavor, the beautiful color, the tender, juicy meat … they all come together to make for a roast that is far more than just adequate or traditional. They make for something wonderful. We hope you give this a try. It's a great way to make lamb fresh and interesting, and the people you serve it to will love it.

Note: If you have a good meat slicer, do slice some of this up for cold cuts. Thin-sliced lamb sandwiches are phenomenally tasty.