Prepare the Roast: Adjust the rack to the bottom of the oven and heat to 425 degrees F. Blot any excess moisture from the roast, rub the Worcestershire sauce over the entire roast, and allow to marinate for 30 minutes, turning it twice. Combine the powdered garlic, onion powder, paprika, and 1 tablespoon coarse-ground pepper in a small bowl; sprinkle the seasoning mixture evenly over the roast, pressing it, and let the roast stand for 20 to 30 minutes. Rub the meat with 2 teaspoons salt, place fat side up in a shallow roasting pan, and roast for 15 minutes. Reduce oven temperature to 325 degrees F and continue to roast until the meat's internal temperature reaches 130 degrees F -- about 2 hours. Let the roast stand for 20 minutes before slicing. Prepare the Gravy: Skim any fat from the liquid that remains in the roasting pan. Whisk the flour and 1/2 cup water together to a paste; set aside. Scrape the drippings from the bottom of the roasting pan, add the beef broth, and stir over medium heat until the mixture begins to simmer. While continuously whisking, add the flour paste and bring to a boil. Reduce heat to medium-low and let simmer for 4 to 5 minutes. If needed, add a little water to thin the gravy. Add remaining salt and pepper; serve warm.