01 -
Heat a large skillet over medium-high heat. Add the ground beef and cook until browned, about 5-7 minutes, breaking it up into small pieces with a wooden spoon as it cooks. Drain excess fat if necessary, leaving about 1 tablespoon in the pan.
02 -
Add butter to the pan with the cooked beef. Once melted, add the diced onion, bell pepper, and minced mushrooms. Sauté until the vegetables are softened and most of their moisture has evaporated, about 5-7 minutes. The mushrooms should be golden brown and the onions translucent.
03 -
In a small bowl, whisk together the beef broth and cornstarch until no lumps remain. Pour this mixture into the skillet, along with the ketchup and Worcestershire sauce. Stir well to combine with the beef and vegetables.
04 -
Bring the mixture to a simmer and cook for 3-5 minutes, stirring occasionally, until the sauce thickens to your desired consistency. If it becomes too thick, add a splash more beef broth. If too thin, continue simmering until reduced.
05 -
Reduce heat to low and add the chopped Provolone cheese to the skillet. Stir gently until the cheese is melted and fully incorporated into the meat mixture, creating a creamy, cheesy sauce.
06 -
While the cheese is melting, lightly toast the hamburger buns either in a toaster, under a broiler, or in a dry skillet until golden brown.
07 -
Spoon the hot Philly Cheese Steak mixture onto the bottom halves of the toasted buns, dividing it evenly between them. Top with the other half of the buns and serve immediately while hot and cheese is still melty.