01 -
In a medium bowl, mix the chicken broth, steak sauce, and Dijon mustard. Set aside.
02 -
In a 12-inch skillet, cook the ground beef over medium-high heat for 7-8 minutes, stirring frequently until browned. Drain and set the beef aside.
03 -
In the same skillet, add butter to any remaining drippings. Add the mushrooms, onion, and steak seasoning. Cook for 7-8 minutes, or until the onions are translucent and the mushrooms are browned.
04 -
Sprinkle flour over the vegetables and cook for 1-2 minutes, stirring frequently until the flour browns and smells nutty.
05 -
Return the cooked beef to the pan and stir in the broth mixture. Simmer for 3-4 minutes or until the mixture thickens.
06 -
To serve, place about 1/3 cup of the beef mixture on the bottom of each toasted bun. Top with 1 tablespoon of shredded Cheddar cheese, then place the top bun.