Steps

• Heat a large skillet over medium heat. Add the ground beef and cook until browned, using a spatula to break it into smaller pieces. Drain excess fat if necessary, and set the beef aside in a separate bowl.
• In the same skillet, toss in the diced onion, green bell pepper, and sliced mushrooms. Sauté them over medium heat until they soften, releasing their juices and aromas to complement the beefy notes.
• Add the browned ground beef back into the skillet with the veggies. Pour in the Worcestershire sauce, stirring well.
• In a separate mixing bowl, whisk together the beef broth and cornstarch until smooth. Slowly pour this mixture into the skillet, stirring constantly. Allow it to simmer until the sauce thickens and coats the beef and veggies evenly.
• Reduce the heat and stir in the milk, allowing the mixture to become creamy and rich. Once it’s well combined, lay the slices of provolone cheese over the top. Cover the skillet and let the cheese melt to perfection.
• Spoon the cheesesteak mixture onto the hamburger buns, top with additional toppings if desired, and serve hot.