01 -
In a skillet over medium-high heat, cook ground beef 2-3 minutes without stirring, then break apart and cook until browned. Set aside.
02 -
In the same skillet, melt butter. Add onions, bell peppers, and mushrooms. Sauté 3-5 minutes until softened.
03 -
Return beef to skillet with vegetables, stir to combine.
04 -
In a bowl, whisk beef broth, cornstarch, ketchup, Worcestershire sauce, salt, and pepper. Pour into skillet, stir well.
05 -
Cook 3-5 minutes, stirring occasionally, until sauce thickens.
06 -
Turn off heat, stir in Provolone cheese until melted and creamy.
07 -
Toast brioche buns. Spoon cheesy beef mixture onto buns and serve hot.