1. In a bowl, combine all rub ingredients.
2. Rinse brisket and pat dry very well. Rub the spice mixture all over both sides of the brisket. (The spice rub makes more than you will probably need. Freeze the rest for another brisket.)
3. Place spiced brisket into a ziptop bag; refrigerate overnight. (If you’re short on time, just let spiced meat come to room temp for one hour. Then continue with the recipe.)
4. Remove from the fridge; allow brisket to come to room temperature. Preheat oven to 350 degrees Fahrenheit (180 degrees Celsius).
5. Heat a large Dutch oven or ovenproof pan over high heat. Add oil and brisket. Sear both sides of the meat for four to five minutes per side until nicely browned. Remove from Dutch oven; set aside.
6. To the same pot, add onions, salt, and pepper. Cook for four minutes until onions are soft and translucent. Add garlic; cook for one minute.
7. Add hard cider, using a wooden spoon to stir it in and scrape up any browned bits from the bottom of the pan.
8. Add remaining ingredients. Bring mixture to a boil; return brisket to the Dutch oven. If you used a pan, pour the sauce and onions over the brisket.
9. Cover the pot tightly. Bake for about one and a half hours.
10. Remove from oven; turn brisket over. Return to oven. At this point, cooking time will vary based on the size of your meat. I suggest giving it another 45 minutes, no matter the size, and after that checking it every 30 minutes until it is soft and tender. Mine took three hours total for a four-pound brisket.
11. Remove from the oven and allow brisket to cool completely in the sauce. (Taking the brisket out of the sauce while it is hot will result in a dry brisket.)
12. If you want to shred the brisket, wait 45 minutes after you take it out of the oven and, while it is still warm, use two forks to shred it in the pot, where it can stay in the liquid.
13. To slice brisket, allow it to cool completely, then remove from sauce and slice against the grain. Garnish with pomegranate seeds, optional.