Crush the juniper berries in mortar and apply liberally all over the meat. Use your hands and rub it in well. Tie it up and put the ham in a plastic bag, and let it “sit” for a good while in the fridge, at least 2 hours.
Fire up your grill and configure it for indirect heat. Dial it in at 150° C / 300° F. Place pecan wood on the coals (a handful if you’re using chips, and 3-4 if you’re using chunks).
Place the roast on the grate, with a thermometer in it. Remove it from the grate when it hits 60-62° C / 140-143° F and wrap it in aluminum foil and a towel, and let it rest for 25-30 minutes. Unwrap, slice and serve!