Light cooker according to instructions. We recommend opening up the intake all the way to let the cooker get extra hot. The top thermometer should read at least 300 degrees.
While the cooker is heating up, prep the meat by trimming any excess fat.
Mix the seasonings (minus the chunky garlic rub) with the mustard and Worcestershire sauce.
Mixing the sauce ingredients.
Hook inserted into the rack of lamb.
Once ingredients are mixed, insert a hook about 3 bones down closer to the thick part of the meat.
Slather the mustard sauce on all sides of the lamb.
Coat the lamb with the chunky garlic-based rub and lightly press in on all sides. This provides extra flavor and texture.
Slathering the lamb in the mustard sauce.
Rack of lamb hanging in the Barrel House Cooker.
Hang the rack of lamb in the cooker on the H-Frame on the top level. If cooking a side dish on the grate in the middle level, the lamb may be resting slightly on the grate.
After 30 minutes, check the internal temp of the meat. For medium-rare, the meat should be 130 degrees. If you plan to reverse sear the lamb, take it off when it reaches about 125 degrees. If you want it more done, let it cook a bit longer before removing from the cooker.
If you'd like to reverse sear the lamb, remove it from the cooker when it's close to being done and take the barrel off the base. Place the grate on the base to form a hibachi grill.
Place the lamb on the hibachi and grill it for a couple minutes on both sides.
Reverse searing the rack of lamb using the hibachi feature.
Finished, sliced rack of lamb.
Remove it from the grill, set it on a cutting board or tray, and cover it to let it rest for 10-15 minutes.