1Season the brisket on all sides with salt and pepper and place in a glass baking dish. Cover with a layer of sliced onions. In a medium bowl, mix together the beer, Elixir and brown sugar. Pour over the brisket and cover tightly with aluminum foil. Bake for 3 hours. Remove foil and cook for an additional 30 minutes. Let brisket rest for 10 minutes before slicing.