I had quite the discussion last week because I asked for a sandwich américain without meat. This led to a large debate amongst the sandwich truck owner and various customers as to whether it could be called sandwich américain if it had no meat.
Since I have had them with fried egg in place of meat in past, and since I believe that it is the fries inside the sandwich which make them 'American', I won the argument, and walked away with a tasty sandwich. I also had convinced at least one other customer to try it that way, much to the consternation of the sandwich seller.