I keep jars of chopped chives in my freezer, and use for cooked preparations. I can’t swear to how their flavor compares, but they look fine.
Mine are regular chives, not chines.
Also, have you seen this thread about “spring onion greens”?
I know they are different alliums, but there might be some ideas there. I made “green seasoning” with a bunch of those.
Regarding subs, I don’t know the source, but I found this.
And this
With regard to growing them without roots, I couldn’t find anything specific to garlic chives, but I don’t see how it can hurt to try!
