Pre-heat the oven to 325 degrees. Let the brisket come to room temperature for at least 30 minutes before cooking. Combine the mustard, sugar and grated ginger in a small bowl. Using your hands or a brush, coat the meat with the rub. Season the beef with salt. Heat the olive in a Dutch-oven or enameled cast-iron casserole pan. Add the brisket when the pan is nice and hot. Sear both sides of the brisket. Once nicely browned on both sides, remove the meat to a plate, leaving the fat and pan drippings. Lower the heat and add the onions. Sauté the onions, adding a little oil if the pan is too dry. Cook the onions until they’ve softened and are translucent, about 10 minutes.

Reduce the heat to medium-low and add the the flour, stirring to cook it through, about 5 minutes. Add the bay leaf, the beer and the chicken stock. Bring it to a simmer. Add the brisket back into the pot and cover. Place the covered pot in the oven. Slow roast the brisket for about 3-4 hours or until the meat is fork tender. Remove the pot from the oven and let it cool. I strained the gravy through a fine mesh sieve- although this is optional. If you’re not serving it right away, store the brisket in its braising liquid. When ready to serve it, bring the pot to a simmer and re-heat the meat. Slice before serving and season the sauce with salt. I add a splash of balsamic or sherry vinegar as needed to balance the flavors.