On the strength of the recommendation in City Paper's feature on Pittsburgh food stands (published a few weeks ago), I went to the stand in front of My Ngoc (on Penn Ave in the strip, around 21st street) to have a 'vietnamese hoagie'. Basically the woman there takes a standard asian chicken-onna-stick, slices up the meat and puts it in french bread with a variety of pickled veggies and sauce. I would definitely recommend her food as making for a great lunch.
Pittsburgh, PA