Heavily season chuck roast with Cattleman’s Grill Eight Second Ride and cook on a grill or smoker indirect in the 250º-275º range. If cooking on a pellet, charcoal or wood fired grill pecan wood adds the perfect flavor. Cook until the internal temperature reaches 165º (check with your trusty Thermapen).
While the roast is cooking, place the remaining ingredients into an oven safe pan.
With the roast at an internal temperature of 165º F (use the Maverick PT-100 thermometer for fast and accurate temperature readings), place into pan on top of the vegetables, pour entire contents of the bottle of Guinness into the pan, and cover tightly with foil. Raise cooker temperature to 350º and cook an additional 2.5 to 3 hours or until roast is fork tender. Once meat is tender, shred all of the meat in the liquid and mix thoroughly and continue to cook until the liquid reduces by half.
Serve meat and vegetables on flour tortillas and top with your favorite cheese and salsa.