Thanks for the info on "rau ram." I'll have to ask to confirm about it the next time I'm there.
Sorry, don't know anything about the "bun bo hue" soup base.
I don't know but I'm going to assume that the broth they use for "bun bo hue" at the place I eat it is the same broth that they use for "pho" which most places make from scratch with beef bones simmered overnight. So, I don't think any instant soup base is going to be able to come close to that.
PS, FWIW, I have purchased a "won ton" soup base (which I still have) that I only used once because it's nothing like what I remember my mother using as the broth when she mad won ton from scratch.