I have been to Shandiz of Mashhad (In Tehran), at least three times thus far. Apparently this is a branch of the original restaurant which is in Mashhad, thus the name!
In Iran you have to be careful, because as soon as a restaurant or a business takes off, impostors pop up to take advantage of the uneducated, and if the authentic one adds something to the name, like "The Original", to distinguish themselves; guess what....
Anyhow, what I do not like about the restaurant, which is an anomaly in Iran and particularly in Tehran, is parking which is a HUGE issue. The restaurant is in a dead end alley in a semi-residential neighborhood. Then there is the wait. Thirty minutes minimum. We have had to wait up to an hour on one occasion. Yes it means they are very popular (and by extension, good), and as such they do not see a need for having a reservation system.
The restaurant is all marble inside so that there is a lot of echo and noise, but that also somehow adds to the ambiance. It is so busy with every seat taken, waiters and busboys shuffling about that It is fun to watch.
Everything on the menu is excellent, so you won't go wrong ordering whatever.
Because of the volume, their service is too efficient. They get you seated and take your order. Food is here. Eat, get the check, get up and pay before you exit. Oh, look. See those guys sitting at your table? They are eating their main course already!!!!
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.