Doing the zombie walk here, "soy sauce".
Many people I met did not know that there is a huge difference between Chinese and Japanese soy sauce on the one hand, and Indonesian soy sauce, which is called "Ketjap", Ketjap Asin or Ketjap Manis. Assuming Aramike talked of Chinese/Japanese soy sauce, I advise you, if you do not know it already, to taste Indonesian soy sauce as well. It is thicker, less salty, hassweetness and quite some flavours and aromes to it, it is more complex a sauce than the Japanese and Chinese soy sauce.
It can be used cold and warm, pure or mixed with Sherry, chicken soup, cayenne pepper or chili, and sugar. This sauce tastes very well if not shying away from making it even sweeter than it is. But it does not compare to the red sweet chilly sauces we also know, it is very different.
Can be used and served to almost everything: Wok-cooking, grilled meat like chicken, beef, fish, on - veggies
, pure rice. Personally, I kill for it.