Preheat oven to 325 degrees. Season brisket with salt and pepper. In a large skillet, heat the oil. Add the brisket, fat side down, and cool over moderately high heat until richly browned, about 5 minutes. Turn and brown on the other side, about 5 minutes longer. Transfer the brisket, fat side up, to a roasting pan.
Add the garlic, onions, carrots, and celery to the skillet and cook over moderate heat, stirring occasionally, until softened, about 10 minutes. Add the bay leaves, rosemary, and chiles, and cook, stirring, for 2 minutes. Add the wine and boil over high heat until reduced by half, about 6 minutes. Add the tomatoes and simmer over low heat for 15 minutes. Pour the mixture over and around the brisket.
Add chicken broth to the skillet and bring to a simmer over high heat. Pour the broth around the brisket. Cover the roasting pan with foil, transfer to the oven and braise until the brisket is very tender, about 3 hours. Transfer the brisket to a platter and cover with foil.
Strain the contents of the roasting pan through a coarse straiiner set over a large saucepan, pushing the vegetables through as much as possible. Boil the sauce over high heat until reduced to 3 1/4 cups, about 20 minutes; season with salt and pepper.
Carve the brisket into 1/3" slices. Pour some of the sauce over the brisket to keep it moist and serve, passing the rest of the sauce at the table.
Best brisket: Refrigerate sliced and sauced brisket for up to two days. Cover with foil and bake in a 350 degree oven until heated through, about 30 minutes.