– Add the ground beef to a large cast iron skillet (it browns very well) and brown until a nice brown crust appears before breaking the beef into pieces.
– Stir the ground beef and brown until a deep crust appears on about 50% of the beef.
– Remove the beef (you can leave the fat) and add the butter and the onions, then the peppers and mushrooms.
– Brown for 1-2 minutes before stirring, then brown for another 1-2 minutes before stirring again.
– Return the beef to the skillet. – In a small cup mix the beef broth and cornstarch together
– Add the ketchup, Worcestershire sauce, salt, black pepper, beef broth/cornstarch mixture to the pan.
– Cook until the mixture is slightly liquid (about 75% of the mixture is above liquid), 3-5 minutes.
– Turn off the heat, add the provolone cheese. – Served on toasted brioche buns.