This classic pot roast should be cooked a day ahead and then cooled thoroughly in order to get clean, sandwich-worthy slices. Otherwise, the hot meat will shred under the knife. If you prefer a hot sandwich, gently heat the meat in the oven or microwave after slicing.
In a medium Dutch oven, heat oil over high. Season meat with salt and pepper to taste, then place in pan and brown (about 4 minutes per side). Remove meat from pan and set aside.
Turn heat to low. Add tomato sauce and cold water to the pot and scrape bottom to loosen browned bits. Return meat to pot and let simmer about an hour. Remove meat from gravy and cool in refrigerator. (If desired, gravy can be reserved, cooled separately, and skimmed of fat.) When cold, slice meat against the grain into ⅛- to ¼-inch slices. Reheat before serving, if desired.
Serve sliced brisket with rye bread and mustard, topped with lettuce, tomato slices, or sauerkraut. Also great with cornichons on the side.