I walk into the lunchroom at work, and know immediately that someone is eating Chinese food. Why is the aroma of Chinese food so readily identifiable?
I’ll just wag that perhaps there are certain spices or seasonings used that are unique just to Chinese food Maybe they tend to be more pungent then other foods, and thats why Tso’s stands out?
Garlic? Shoyu? Ginger? Black bean sauce?
Some common ingredients that aren’t so common to the Western nose:
ginger
oyster/fish sauce
sesame oil
Feel free to add.
My all time fav is fermented bamboo shoots in chili oil. Yum. But the aroma always gets me banned from public microwaves.
Mmmmmm… Fermemnted soybeans in salt solution. American soy sauce is basically just a method of getting your food soaked in sodium chloride. The real stuff is much mroe interesting.
Then again 
I like salt. 
And I don’t like cabbage.
Are you talking about Natto Beans? I always thought that was a Japanese dish?
I love it but everyone hates the smell. 
Nonono, standard soy sauce. I read about it in the “Salt” book or “Book on Salt” or something equally interestingly titled. Actually, an interesting read if you’re into economics or sociology.
In any case, salt is an excellent way of keeping most bacteria out of foods. I’m sure that there are some bacteria that don’t mind being in a 26% salt solution (I believe that that, by weight, is the ratio of the most salt you can put into an amount of water at room temperature before it starts crystallizing), but the ones which are important to keep out of the human gastrointestinal tract can’t handle the horrible little ions.
What was I tlaking about? Right - soy sauce - the Eastern main dietary supply of salt for centuries. Excellent stuff.
The American version doesn’t taste terribly different IMO from a 10% salt solution - I know, I’ve tried. There’s some extra something… but not anything like the goodness in authentic Chinese soy sauce,.
Real soy sauce all the way.
I’d guess the ginger/garlic/soy smell, combined. Or sesame, as hapaXL said. Or the feeling of msg vapours. 