In a large Dutch oven, heat the olive oil over high heat until smoking. Season the meat liberally with salt and pepper. Sear in the pan for 4 to 5 minutes per side. Remove once dark golden brown and set aside.
Add the onions, carrot, celery and garlic and cook until the vegetables are starting to brown, about 8 minutes. Add the wine and bring to a boil. Reduce by half, about 3 to 5 minutes, then add the beef stock.
Add the brisket back in, along with the thyme and bay leaf, and bring up to a simmer. Place a lid on the pot and cook at a low temperature for 2 1/2 to 3 hours, or until the meat is fork tender. Serve the brisket with the sauce and vegetables.