Slice steak into thin slices. Brown in skillet, add onion, mushrooms and bell pepper until veggies are soft. Add worsteshire sauce, garlic powder, salt and pepper. Let this simmer as long as possible.
Cut centers out of hoagie rolls, put mayo and cheese on bottom, drain some steak mixture, put in roll, mayo the top piece and put back on sandwich. Can add more cheese on top of steak if desired.
For best results, put the finished mixture into a crock pot and let simmer all day.