The onions on NYC hot dog carts?

How are those onions prepared They're in some sort of light brownish/orangish sauce, only slightly damp, and don't have any onion "burn." I grew up on them but only now am realizing I don't know what they are.

Possibly there are caramelized. If you cook them right (just by themselves) they will give up some of their fluid and turn brown. That is just guess, I have never been to NYC and therefore never seen the onions of which you speak.

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