Philly Cheesesteak Sloppy Joe

Heat a large skillet over medium high heat. Add ground beef and brown for about 5 minutes, breaking it apart with a wooden spoon. Add onions, green peppers and mushrooms. Saute until veggies are soft, about 5-7 minutes. Stir in beef stock and steak sauce. Reduce heat, and simmer for 5 to 10 minutes, until the sauce reduces by half. Season to taste with salt and pepper.

You can toast the buns if desired. Place a slice of cheese on the bottom of each bun, and spoon meat over top. The heat from the meat should melt the cheese.

Adapted from Pass the Sushi.