Up front, this is a stir-fry dish in the style of Pad Thai. It is a matter of ingredients. The local supermarkets do not carry all of the items needed to make an “authentic” Pad Thai. I have had to make some substitutions. From time to time I come across a source and stock up on a few more authentic items. But for the most part the recipe as given here is as I would make it from the local supermarket. How close is it? Over the years I have had Pad Thai from several different vendors. All were identifiable as Pad Thai and yet all were slightly different. I think if I slipped a bowl of this Pad Thai among the others, it would be accepted as easily as the others.
There is one ingredient, available in most asian markets, you need for Thai cooking, that is nam pla, or fish sauce. A pungent sauce, it thankfully looses its aroma when added to the cooking food, but it imparts a particular flavor needed for Thai-style dishes. Soy sauce is a poor substitution.
I like the shrimp Pad Thai, Other mild-flavored fish or shell fish as well as chicken can be substituted. You can omit the shrimp and fish sauce altogether, substitute soy sauce and use tofu to make it a tasty vegetarian dish. Remember, this dish contains peanuts and can cause a serious allergic reaction.
In collecting recipes over the years I have come across several variations and have added them at the bottom of the ingredients list as optional, possible additions to your Pad Thai dish should you choose.