Preparation Preheat the oven to 325. Since the meat is so thick and dense, it's a good idea to pull it out of the refrigerator a half hour before going in the oven. Peel and slice the onions into 1/2-inch thick onion rings. Scatter the rings across the floor of a roasting pan. Lay the meat fat-side down over the onion slices and season well with salt and pepper. Cover the meat with the red wine, then the Heinz Chili Sauce, and then the onion soup mix. Cover the pan either with a lid or with foil and roast at 325 for 4 hours, basting every hour. When you baste, be careful not to wash all of the sauce from the top of the meat. Just ladle the juices carefully over the meat. After 4 hours, pull the meat from the oven and uncover to let cool a bit. Turn the oven down to 225. After the meat has cooled enough to handle, place it on a cutting board fat side up, and holding a long slicing knife horizontally, slice off the layer of fat and discard. Cut the brisket into quarter-inch thick slices across the grain. The grain on a brisket is very apparent and easy to read. You want to cut across the grain. Picture a bundle of sticks and you want to cut them into sheets of twigs. This is a very important step in the recipe because by the time the meat is finished it will be falling apart and much more difficult to slice. At this point, it is still slightly tough and easier to get clean slices. If you get some shredded brisket with it, that's ok, that's good too. Return these slices to the sauce in the pan, making sure they are submerged in liquid and mixed in with the onion slices. Return the pan to the oven (now set at 225) for 2 more hours, uncovered. Again, this is an important step. Leaving it uncovered allows the sauce to thicken into what the be almost as amazing as the meat.