1. Begin by trimming the fat on the lamb leg to have an even 1/4 inch across the whole leg. Trimming the fat down will allow it to render as it smokes.
2. Mix together all rub ingredients until well incorporated, before applying liberally across the full surface of the lamb. If needed, you can brush on a light coat of vegetable oil, to help the rub adhere.
3. Place lamb on a 225F-250F smoker until it hits your desired internal temperature. Lamb is generally considered to be perfectly cooked when it hits about 125F-130F.
4. As the lamb cooks, prepare the blackberry sauce. Place all sauce ingredients into a medium sized sauce pan, on a medium heat. Bring to a light simmer (approximately 5 minutes) and stir constantly until well incorporated.
5. Once lamb is cooked, remove from smoker and allow to rest for 30 minutes, lightly tented in foil.
6. Carve lamb into 1/4 inch slices, slicing against the grain to allow for the most tender slice possible.
7. Smoke until the pork is crispy and the sausages have cooked all the way through-approximately 30-45 minutes.
8. Serve lamb with the blackberry sauce and your favorite, Sunday roast sides.