Preheat your smoker or oven to 225°F to ensure a low and slow cooking process.
In a small bowl, combine the sea salt, black pepper, garlic powder, onion powder, and smoked paprika to create a clean dry rub.
Coat the beef brisket thoroughly on all sides with the spice rub, pressing it firmly into the meat to form a crust.
Place the brisket in the smoker and cook until the internal temperature reaches 195°F, allowing the fat to render slowly.
While the meat cooks, whisk together the tomato paste, apple cider vinegar, maple syrup, and coconut aminos in a small saucepan over low heat to create the glaze.
During the final 30 minutes of smoking, brush the BBQ glaze generously over the exterior of the brisket to caramelize.
Toss the trimmed and halved Brussels sprouts with olive oil and roast at 400°F for 20 minutes until they are crispy and golden brown.
Remove the brisket from the heat and let it rest for at least 15 minutes before slicing thinly against the grain to serve.