Preheat your smoker or oven to 225°F for low and slow cooking.
In a small bowl, combine the sea salt, black pepper, garlic powder, onion powder, and smoked paprika to create a dry rub.
Rub the spice mixture evenly over all sides of the beef brisket flat, pressing it into the meat to ensure it adheres.
Place the brisket in the smoker and cook until the internal temperature reaches 165°F, which typically takes several hours.
Spritz the brisket with apple cider vinegar every hour after the first three hours to maintain moisture and build a bark.
Wrap the brisket tightly in butcher paper or foil and return it to the heat until the internal temperature reaches 202°F.
Remove the brisket from the heat and let it rest for at least 30 minutes to allow the juices to redistribute.
While the meat rests, toss the broccoli florets with olive oil and roast at 400°F for 15 minutes until tender-crisp.
Slice the brisket against the grain into thin strips and brush with the sugar-free BBQ sauce before serving alongside the roasted broccoli.