Preheat your oven to 300°F (150°C).
Pat the brisket dry with paper towels. Rub the olive oil all over the brisket.
In a small bowl, mix together the kosher salt, black pepper, garlic powder, onion powder, smoked paprika, and dried thyme. Rub this spice mixture evenly over the brisket.
In a large roasting pan, place the sliced onion and minced garlic. Lay the seasoned brisket on top of the onions and garlic.
Pour the beef broth and Worcestershire sauce around the brisket in the pan.
Cover the roasting pan tightly with aluminum foil. Place it in the preheated oven and roast for about 4 to 5 hours, or until the brisket is tender and easily pulls apart with a fork.
Remove the brisket from the oven and let it rest for at least 20 minutes before slicing.
Serve the brisket with the pan juices drizzled over the top.