It depends on your budget or who's paying...they like to recommend a series of dishes which help the pallete adjust to the cuisine. When I last went there, the Peruvian influence was being accentuated ie. very hot sauces/spices.
I haven't I must admit yet reached the hallowed halls of Nobu in London but if the black cod in miso is on the menu (it's supposedly one of the definitive Nobu dishes so I'd be surprised if it wasn't)make sure you order it. I ate it in New York and it was sublime.