Are but laurence, most chinese restaurants use Hoisin sauce, but the original sauce that accompanies Peking Duck is sweet bean, and the only place that used to serve that was in Willesden (1st class establishment / awards galore) that I first tried the wonderful duck with only spring onions (scallions) as again is the original meal..
It is like fried crispy won-ton - USA were first to do it like that the Chinese only ever put won-tons in soup..there are quite a few Westernised foodstuffs...
Chow Mein