In a large skillet over medium heat, combine the beef broth, Worcestershire sauce, onion powder, garlic powder, and black pepper. Stir well to combine.
Add the sliced roast beef to the skillet and cook until heated through, about 5-7 minutes. Stir occasionally to ensure even heating.
While the beef is heating, preheat your oven to 350°F.
Slice the hoagie rolls in half lengthwise and spread the softened butter on the cut sides.
Place the hoagie rolls on a baking sheet, cut side up.
Once the beef is heated, spoon the beef mixture evenly onto each hoagie roll.
Top each sandwich with shredded provolone cheese.
Bake in the preheated oven for 10-12 minutes, or until the cheese is melted and bubbly.
Remove from the oven and let cool for a minute. Garnish with chopped parsley if desired.
Serve warm and enjoy!
