Philly Cheese Steak Sloppy Joes

1 pound lean ground beef
2 tablespoons butter
1 small yellow onion diced
1 small green bell pepper diced
8 ounces brown mushrooms minced
2 tablespoons ketchup
1 tablespoon Worcestershire sauce
1/2 teaspoon Kosher salt
1/2 teaspoon fresh ground black pepper
1 tablespoon cornstarch
1 cup beef broth
8 ounces Provolone Cheese Slices chopped (use 6oz if you don’t want it very cheesy)
6 brioche hamburger buns

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