Moo goo gai pan ????

The first time I heard of 'moo goo gai pan' said in American/English years ago, I had no idea what it was. Then I figured it out it must be chicken with mushroom, still took me many years later to figure out what 'pan' is in Chinese till I Google and found out it is ?(slices). This dish name has appeared in many American movies or tv whenever Chinese food is mentioned, even The Simpsons also