Mix ingredients for herb paste together, brush on the outside of the boneless lamb roast (leave the string mesh on the meat to hold things together during the cook)
Smoke on indirect heat at 275 degrees until internal temperature reaches 130-135 degrees.
Optional: Sear outside of the roast on both sides for a few minutes at the end of the cook.
Remove from heat, allow to rest at least 10-15 minutes.
Serve with your favorite mutton sauce. (We used creamy horseradish sauce, which made the roast remind us of prime rib!)