@liuzhouI think this is a good entry for the misconceptions about Chinese food thread. Growing up, when one first sat down at the table in a Chinese restaurant in suburban NYC, they would put down the dish of fried noodles discussed elsewhere, along with the "duck sauce" and "Chinese mustard" which is like a tan/yellow mustard with either horseradish powder mixed in or something like that - it was sinus clearing. Many people would use the Chinese mustard to season their dishes...
Even today, in NYC (not in Chinatown) when I get Chinese takeout/delivery, they include a handful of packetized sauces including soy sauce, "duck sauce" and the Chinese mustard.