Season the brisket using all of the seasoning mix. Wrap the brisket and refrigerate for at least 2 hours, or overnight if possible. About 30 minutes before you’re ready to cook, take the brisket out of the fridge to bring it up to room temp.
Heat the smoker to 225° (107°C) or 250°F (121°C).
Place the brisket, fat-side down, on the grill. Insert a meat thermometer probe into the thickest part. Close the lid and cook for about 5 hours, or until the internal temperature reaches 160°F (71°C).
Remove the brisket and wrap it in butcher paper or tin foil to form a packet around the meat. Place it back on the grill at 225°F (107°C) until the internal temperature reaches 200°F (93°C), between 2 1/2 and 5 hours.
Remove from the grill and rest, still wrapped, for at least 30 minutes to 2 hours before slicing.