Pre-heat your smoker or oven to 250° F.
Prepare the chuck roast by slathering it down with mustard till coated all over.
Sprinkle the chuck roast generously with sweet rub seasoning to give it a good thick coating to get a nice crust when cooking.
Place the meat on the grill or on a sheet pan in the oven. Allow to cook until the internal temperature reaches 175° F, about 5 to 6 hours.
When cooked remove meat from the grill and allow to rest for 10 minutes.
Cut the roast into 1 inch cubes and transfer to a casserole dish or aluminum foil pan.
Cover meat with BBQ sauce and sprinkle with brown sugar. Tossing meat till completely coated.
Cover dish with tin foil and place in oven to braise for one and a half hours until they are fall apart tender.
When tender enjoy as is or served over mashed potatoes.
