Whisk together BBQ Sauce and cactus pear syrup. Set aside
Lightly brush meat of lamb with dijon mustard. Season thoroughly with Southwest Seasoning. Set out for 15 minutes before placing on smoker. Place foil over the bones to keep them from burning.
Smoke until internal temperature of 110 degrees is reached. Remove from smoker (or cold side of grill) and place on searing hot side of grill.
Grill until internal temperature of 130 degrees has been reached (for medium rare.) As temperature hits about 5 degrees below your desired temp, glaze with sauce. Remove from grill, lightly cover with foil, and allow to rest for 5 minutes before slicing. Serve with additional sauce.