Heat a large skillet over medium-high heat and add the ground beef.

Let it cook undisturbed until a deep brown crust forms, then break it apart and continue browning.

Remove the beef from the skillet, leaving the fat behind.

Add butter, onions, bell peppers, and mushrooms.

Let vegetables brown for 1–2 minutes before stirring, then repeat for deeper flavor.

Return the beef to the pan.

In a small bowl, mix beef broth and cornstarch until smooth.

Add ketchup, Worcestershire sauce, salt, pepper, and the broth mixture to the skillet.

Cook for 3–5 minutes until the mixture thickens and becomes slightly saucy.

Turn off the heat and stir in provolone cheese gradually until melted and creamy.

Serve the Philly Cheese Steak Sloppy Joes on toasted brioche buns.