Blend all ingredients together to create the marinade.
Cut the chuck roast into 3-4-inch chunks and place in a gallon size bag.
Cover the chuck roast with the marinade and leave overnight or at least 4 hours.
Begin by starting your fire, let your fire burn down and bring the smoker to 225-250 degrees.
Place a pot of water in your smoker near the fire to make sure the inside of the smoker is humid during the cooking process.
Place your chuck roast and the marinade in a cast-iron Dutch oven. Place your Dutch oven in the smoker without the lid.
Close your smoker and smoke for 6-8 hours, until the roast is fork-tender, then remove from fire and shred.
Next, place back on the smoker and continue cooking.
Let the juices evaporate a little more; however, do not let it run dry. You want a little of the juice to keep the roast nice and moist.