1 1/2 tablespoon ancho chile powder
1/2 tablespoon garlic powder
1/2 tablespoon dried oregano
1/2 tablespoon celery salt
1/2 tablespoon smoked sweet paprika
1/2 tablespoon ground coriander
1/2 tablespoon dry mustard powder
1/2 tablespoon ground allspice
Kosher salt
Pepper
One 7-pound boneless lamb shoulder, excess fat trimmed
Canola oil, for brushing
4 cups applewood chips, soaked in water for 1 hour and drained
Sorghum Barbecue Sauce

1. In a medium bowl, whisk the chile and garlic powders with the oregano, celery salt, paprika, coriander, mustard powder, allspice, 1 tablespoon of salt and 1/2 tablespoon of pepper.
2. On a rimmed baking sheet, open up the lamb shoulder and rub the spice mix into the meat. Roll up the meat and tie at 1-inch intervals with kitchen string. Cover the lamb shoulder and refrigerate for at least 8 hours or overnight.
3. Remove the seasoned lamb shoulder from the refrigerator. Brush it all over with oil and season with salt and pepper; let the meat stand at room temperature for 30 minutes. Meanwhile, light a hardwood charcoal fire in a smoker. When the coals are ready, scatter the wood chips evenly over them. Attach the indirect cooking plate and heat the smoker to 225°.
4. Smoke the lamb fat side up for 6 to 7 hours, basting with some of the Sorghum Barbecue Sauce during the last 30 minutes. The lamb is done when an instant-read thermometer inserted in the center registers 185° and the meat is very tender; monitor the temperature throughout the cooking process and adjust the air valves as needed.
5. Transfer the lamb to a carving board and let rest for 20 minutes. Discard the kitchen string. Thinly slice the lamb across the grain and serve with the barbecue sauce. 

MAKE AHEAD

The smoked lamb can be refrigerated overnight. Bring to room temperature, then reheat gently in a covered baking dish.

SUGGESTED PAIRING

California's Santa Barbara County produces beautiful, concentrated Syrahs that are excellent with barbecued dishes like Flay's smoked lamb.