Preheat your oven to 300°F.
In a large, heavy-bottomed pot or Dutch oven, heat the olive oil over medium-high heat. Season the brisket with salt and pepper, then sear it in the pot for about 4-5 minutes on each side until browned. Remove the brisket and set it aside.
In the same pot, add the sliced onion and cook for about 5 minutes until softened. Add the minced garlic and cook for an additional minute.
Stir in the beef broth, red wine, tomato paste, Worcestershire sauce, brown sugar, thyme, and rosemary. Bring the mixture to a simmer.
Return the brisket to the pot, fat side up, and cover it with a lid. Transfer the pot to the preheated oven and braise for 3 to 4 hours, or until the brisket is tender and easily shredded with a fork.
Once done, remove the brisket from the pot and let it rest for 15 minutes before slicing. Serve with the braising liquid spooned over the top.