I know folks are perpetually looking for a variety of Vietnamese/SE asian herbs to replicate the true tastes they have had in asia.
I am just posting to note that the Hong Kong Supermarket in Sunset Park Brooklyn is at this time carrying several different to me-unidentifiable fresh herbs, packaged, labelled as "vietnamese mint" in their produce section. Tho none looked like rau ram (viet coriander) to me. A couple have smallish leaves, one has fan-shaped leaves with red stems, etc. They also carry the thai basil, culantro (sawtooth herb) lemon grass etc. in that section, and a lot of other stuff in their frozen food section (sator beans, galangal, turmeric root, etc.
Perhaps these items are also turning up in their branches elsewhere - but I would be interested to see if a maven of these cuisines could identify these differing herbs and their uses.