French Dip Sandwich

Name: French Dip Sandwich
Prep time: 5 min
Cook time: 10 min
Total time: 15 min
Yield: 4
Ingredients: Ingredients; Sandwich; 1 lb roast beef, thinly sliced (from the deli or homemade); 4 hoagie rolls or French rolls; 4 slices provolone or Swiss cheese (optional); 1 tablespoon butter (for toasting rolls); Au Jus (Dipping Sauce); 2 cups beef broth; 1 tablespoon Worcestershire sauce; 1 tablespoon soy sauce (optional); 1 teaspoon garlic powder; 1 teaspoon onion powder; Salt and pepper, to taste