In a large skillet over medium heat, add the lean ground beef and cook until browned, breaking it up. Once the beef is browned about halfway, stir in the onion and bell peppers. Finish cooking until beef is fully browned.

Drain any excess grease as needed.

Stir in the Worcestershire sauce, brown sugar, salt and pepper.

In a small bowl mix the cornstarch and beef broth. Pour the mixture into the skillet with the beef mixture and stir to combine. Cook until the liquid cooks down most of the way.

Remove from heat and add the provolone slices to the top, let melt. Spoon onto toasted buns and serve!