Peter is very right, you need to go to Vietnam. I think there are basic problems why the renditions aren’t as good:
1/ It’s difficult to find quality Vietnamese fish sauce outside Vietnam, restaurants use cheaper Thai fish sauce, might not be the same quality.
2/ You can’t find abundance herbs nor same types outside Vietnam without paying a high price.
3/ Street food are in fact very specialized, each stall cooks the same dish everyday for years, they become expert. A restaurant outside Vietnam cook all types of dishes and therefore more a generalist.
(Very strange. Actually wrote this draft for years, and forgot to post it)
