Preheat oven to 300 degrees F and arrange a rack in the middle of the oven.
Mix together garlic powder, onion powder, kosher salt and pepper. Rub onto the beef round and set aside while prepping the rest of the ingredients. (There may be some leftover rub.)
Heat oil in a large Dutch oven over high heat. Add beef round and brown each side until well caramelized, about 2 to 3 minutes per side. Remove from the Dutch oven and set aside.
Lower the heat to medium and add the celery, onion and bell pepper. (Don't worry about the dark brown "fond" stuck to the bottom of the pot. This stuff will add great flavor to the final dish.) Saute the vegetables until tender, about 5 to 7 minutes. Add garlic and saute for another minute. Stir in the flour and continue to cook until no white is visible, about 1 to 2 minutes. (This is important in order to cook the "raw" taste out of the flour.)
Pour in the beef stock. Increase heat to medium-high and, stirring frequently, allow the sauce to thicken, about 5 to 7 minutes. Add red wine, Worcestershire sauce, and a generous seasoning of salt and pepper. Nestle the beef round into the sauce.
Cover the pot and cook in the oven for 4 to 4 1/2 hours until meat can easily be shredded with a fork. Remove the beef round to a cutting board and shred into long strands. Chop these pieces, if desired. Add the chopped meat back to the gravy. Adjust seasoning, to taste. Reheat the meat on low heat, if necessary.
Serve the beef and gravy on toasted or steamed baguettes with a generous dollop of mayonnaise, shredded lettuce and sliced tomatoes. And while provolone cheese is not a traditional accompaniment, I think it's a tasty one. Oh, and don't forget your napkins!