Slow Roasted Barbecue Brisket

0 Preheat your oven to 300 degrees 
1 Combine the dry rub ingredients in a small dish and set aside for now
2 If your brisket has a fat cap, trim it and discard 
3 Dry the brisket with paper towels and use about 3/4 of the dry rub to generously season the brisket on all sides 
4 Add a few tablespoons of a neutral oil into a large cast iron skillet placed over medium heat
5 Place the seasoned brisket into the skillet and sear on both sides
6 Transfer the brisket onto a plate and set aside for now
7 Add the thinly sliced onions into the skillet and sauté until softened (about 5 minutes)
8 Add 4 cloves of minced garlic, 2 tablespoons of tomato paste, 1 tablespoon of brown sugar and the rest of the spice blend and mix to combine
9 Bring the mixture to a simmer and nestle the seared brisket into the liquid 
10 Tightly cover the skillet with foil and and transfer into a 300° oven
11 Roast for 2 hours
12 Carefully flip the brisket, recover the skillet and roast for another 1 to 1 1/2 hours or until the brisket is very tender and reaches an internal temperature of 200°
13 Transfer the skillet out of the oven and let the brisket rest for 15 minutes 
14 Transfer the brisket onto a cutting board and place the skillet over medium heat
15 Whisk in a cup of your favorite barbecue sauce and simmer until thickened to your desired consistency 
16 Thinly slice the brisket and nestle into the barbecue sauce