Rub the salt into the meat very well. Coat the meat with the flour.
Heat the vegetable oil in a large cast-iron Dutch oven and sear the roast on all sides. Transfer the roast to a platter and scrape the pan to loosen the drippings. Add the French onion and mushroom soups and 3 3/4 cups water to the pan. Bring to a boil, then reduce the heat to a simmer. Return the roast and its juices to the pan, cover and cook until the meat is tender, about 3 hours. Remove the roast to a platter or cutting board to rest.
Slice and serve with the pan gravy.
Adapted from Home Cooking with Trisha Yearwood (c) Clarkson Potter 2010