Preheat the oven to 300 degrees Fahrenheit and pat dry the brisket with paper towels.
In a small bowl, mix the salt, black pepper, oregano, thyme and paprika. Rub the brisket with the spice mix.
Heat the oil over medium high heat in a heavy flameproof roasting pan or in an oven-safe Dutch oven just large enough to fit the brisket and vegetables snugly.
Add the brisket to the pan and sear the meat on both sides until a nice golden crust appears on the surface, about 10-12 minutes. Transfer the meat to a platter.
Add the onions to the pot and cook stirring frequently for about 8 minutes or until the onions soften. Add the carrots and celery and cook, stirring often for about 2 minutes. Add the garlic and cook for about a minute or until fragrant.
Add the beer and scrape the bottom of the pan with a wooden spoon to release all the brown bits stuck at the bottom. Stir in the crushed tomatoes, broth and bay leaves. Mix to combine.
Place the brisket fatty side up in the pan along with any accumulated juices from the platter. Cover the pan tightly with aluminum foil (preferably heavy duty) or a lid.
Transfer to the oven and bake for 3 1/2 to 4 hours or until the meat is tender.
Transfer the brisket to a cutting board and let it rest for about 15 minutes. Scoop the vegetables out of the pan and transfer to a plate. Keep warm.
Skim off some of the excess fat from the sauce and remove the bay leaves. Slice the meat thinly across the grain (1/8 - 1/4-inch-thick slices) at a slight diagonal. Return the slices to the pot overlapping them at an angle.
To serve, place the vegetables and sauce on a platter and top with the brisket. garnish with parsley (optional)