01 -
Toss the ground beef in a hot cast-iron skillet but don’t touch it right away. Let it brown and develop a crust on at least half before breaking it up.
02 -
Take the browned beef out of the pan and save it for later. Keep the fat in the pan—you’ll use it soon.
03 -
Toss the butter, diced onions, mushrooms, and bell pepper into the skillet. Let them cook without stirring for a bit to get browned, then give them a quick mix. Repeat until evenly golden.
04 -
Add the cooked beef back into the skillet to mix with the veggies.
05 -
In a small cup, blend cornstarch with beef broth to create a smooth mixture.
06 -
Stir the cornstarch mix into the skillet along with Worcestershire sauce, ketchup, salt, and black pepper. Mix evenly.
07 -
Simmer the pan for about 3-5 minutes until most of the mixture is above the liquid, but it’s still a little saucy.
08 -
Turn off the stove and stir the chopped Provolone in until it’s melted.
09 -
Pile the beef mixture onto toasted buns straight from the skillet.