Cook Veggies:
Heat olive oil in a skillet over medium heat. Sauté onion, bell pepper, and mushrooms (if using) until soft, about 5–6 minutes.

Brown Beef:
Add ground beef to the skillet and cook until browned. Drain excess fat if needed.

Add Flavor:
Stir in Worcestershire sauce, ketchup, garlic powder, salt, and pepper.

Make Sloppy Sauce:
In a small bowl, whisk together beef broth and cornstarch until smooth. Pour into the skillet and stir to combine. Simmer for 3–4 minutes until thickened.

Add Cheese:
Turn off heat and stir in provolone cheese until melted and the mixture is creamy.

Assemble Sloppy Joes:
Spoon mixture onto hamburger buns. Serve warm and enjoy!