In a saucepan sauté onions in the butter

Add wine and boil just enough to release the alcohol smell

Add beef broth, Worcestershire sauce, salt & pepper, cover and reduce to simmer

Add cooked beef and drippings to au jus mixture bring to a boil, cover and simmer until the meat has absorbed the au jus flavor

Toast hoagie roll with provolone cheese, add beef and serve with a side of au jus