1. Toast cacao nibs over medium heat in a dry skillet about 2 minutes. Crush nibs, red pepper flakes, pepper, and salt with a mortar and pestle. (You can also grind together in a spice or coffee grinder).

2. Coat brisket with cacao rub generously on all sides.

3. Chill covered for at least 12 hours or up to 2 days.

4. Preheat oven to 350° F.

5. Heat 2 Tbsp olive oil in a large cast iron roasting pan or Dutch oven over medium heat.

6. Sear brisket, fatty side down, turning after about 12 minutes. Sear other side for 8-10 minutes and then with tongs, quickly sear edges of the brisket. Remove to a sheet pan or large platter.

7. Heat remaining 2 Tbsp olive oil in the pan over medium-high heat. Add the onion, salt, and pepper and cook until the onion is beginning to caramelize.

8. Add celery, garlic, and thyme and stir thoroughly to coat.

9. Add vinegar, Worcestershire sauce, and 4 cups of beef stock.

10. Submerge the brisket in the pan, fatty side up. If you need to add more water, add just enough to submerge.

11. Bring to a simmer on the stove top, and then immediately place into heated oven.

12. Braise for at least 3 hours.

13. Check the brisket. It should be very tender with the tip of a knife easily slicing into the meat. If not, braise an additional 20 minutes and check again.

14. When the brisket is knife tender, increase the oven temperature to 425° F and continue to let it cook, uncovered, until the liquid is reduced by three-fourths and the top of the brisket is crisp, about an hour.

15. Remove from oven and discard the garlic, onions, and celery.

16. Let cool slightly for 5-10 minutes, transferring to a cutting board.

17. Slice with a serrated knife and enjoy!