I've only bought it in Portland, usually at Zupan's, which is sort of like Whole Foods. In terms of preparation, my girlfriend at the time typically made a sashimi salad out of it, similar to why you get from Matsuhisa, and it was always delicious. Not especially difficult to make either; basically place the filets between bamboo planks after dousing them in a citrus based (including ponzu and/or yuzu sauce) marinade, which does the "cooking".

Speaking of preparation, I went to a restaurant here last night called Ministry of Crab (first floor of Barbarossa in People's Park for those of you who know Shanghai). They only offer one type of fish each day, and the quality is usually decent. You just get to choose between 3 cooking styles: teriyaki (no thanks), butter, and olive oil plus a little soy sauce.

I tried each of the latter, and felt a 10-year old could have done a better job. The fish itself (Australian sea bass) wasn't mind blowing, but was certainly up to my standards. Unfortunately, the chefs didn't give it the love it deserved. Had I cooked it myself, I probably would have gone with olive oil, lemon slices, white wine, maybe ginger and/or garlic, and wrapped it in foil prior to baking. But, the foil isn't necessary, and the same ingredients work fine on the stove top. I almost never bread sea bass, but doing so would have resulted in a better final product than what the restaurant dished out.

I don't plan on returning to Ministry of Crab because, apart from the disappointing fish, those guys are way too into themselves.

My favorite fish dish in Shanghai is Cod Mediterranean, and it's available at a handful of mid-range restaurants. Sure, it includes a lot of "stuff" in addition to the fish, but the fish always makes its presence known. Supposedly, it comes from Iceland.