Preheat your smoker to 225°F using oak or hickory wood for an authentic Texas flavor profile.
Trim the beef brisket flat of any thick silver skin, leaving a very thin layer of fat to ensure the meat stays succulent during the long cook.
In a small bowl, combine the sea salt, black pepper, garlic powder, onion powder, and smoked paprika to create a classic dry rub.
Apply the dry rub generously to all sides of the brisket, pressing it into the meat to form a crust.
Place the brisket in the smoker and cook until the internal temperature reaches 165°F and a dark bark has formed.
Wrap the brisket tightly in butcher paper and return it to the smoker until the internal temperature reaches 203°F.
Remove the meat from the smoker and let it rest, still wrapped, for at least 30 minutes to allow the juices to redistribute.
While the meat rests, whisk together the tomato paste, apple cider vinegar, maple syrup, and yellow mustard in a small saucepan over low heat to create the BBQ glaze.
Toss the shredded cabbage with the olive oil and a splash of extra vinegar to create a crisp, clean side slaw.
Slice the rested brisket against the grain into thin strips and serve immediately with a light brush of the warm BBQ glaze.