To a large skillet over medium heat add the ground beef break the beef up and cook it for 2 minutes. After 2 minutes of cooking add in the diced onion, diced bell pepper, and mushrooms continue to cook until the beef is cooked through.
Once the ground beef is cooked and vegetables are tender add the ketchup, Worcestershire sauce, salt and pepper stir to combine the ingredients.
To the 1 cup of beef broth whisk in the corn starch to create a cornstarch slurry.
Stir in the beef broth cornstarch slurry. Let simmer until the sauce thickens.
Place slices of provolone cheese over the top of the sloppy joe mixture cover with lid and let the cheese melt down.
Optional: While cheese is melting toast the hamburger buns in a skillet with butter until golden in color.
Generously fill the hamburger buns with the sloppy joe mixture. Enjoy!