If we just want them to change color we can do that a whole lot faster than 10 minutes. But you wouldn't like the taste. :)

> Browning, unless we’re talking about burning onions, is caramelisation

No, its not. Heck, even “caramelizing” onions mostly isn’t caramelization, its Maillard-reaction browning combined with slower cooking so that the cooking is more complete, retaining less of the firm texture.

https://www.thespruceeats.com/how-to-brown-onions-913397