Heat oven to 350º. Season brisket with salt and pepper. In a Dutch oven, or in a deep, heavy-bottomed, ovenproof pan with lid, heat olive oil over medium-high setting and brown brisket on both sides, about 5 minutes per side. Remove brisket to a plate.

Add onion, carrot, and celery to the pot and saute about 5 minutes. Add garlic and sauté about 5 minutes more. Add wine, thyme, and bay leaves. Bring to a boil and cook until liquid is reduced by half, about 10 minutes.

Stir in tomato paste, Worcestershire sauce, and stock, and bring to a boil. Add brisket and any juices that have accumulated back to the pot. Nestle the meat into the vegetables and liquid. Cover, and cook in oven about 3 hours or until very tender, turning meat over every 45 minutes or so.

Transfer meat to platter and let rest 20 minutes. Strain pot juices and discard solids. Let pot juices sit until the fat separates. Skim off and discard the fat. Add pearl onions; then bring the sauce to a boil and reduce by half. Slice meat thinly across the grain and place on a serving platter. Spoon sauce over the top, and serve remaining sauce in a gravy boat.