Blue cod was my favourite fish when I lived in Auckland. It was nice and fresh and best fish cook as a steamed fish in New Zealand. In Cantonese cooking, the steamed fish usually calls for the freshest you can find, that's why a lot of Cantonese restaurants have those big fish tanks... The only way to make sure the customers get the most fresh fish...
It's hard to have a swimming blue cod, because it's a sea fish, so selecting the right blue cod is very important, if you want to have it steamed.
Since we moved to Australia, barramundi and coral perch are usually on the list for steamed fish dishes, local, fresh and nice sweet meat. But every now and then, there are some nice blue cods, from New Zealand, fresh from our local fish mongers.
Steamed fish is usually quite simple - after all, fresh produce speaks for itself.
Rub the cleaned fish with a bit of salt, inside and out, set aside for half an hour. Slice a few pieces of fresh ginger, and steam the fish for roughly 10 minutes. While the fish is in the steamer, juvienne some spring onion (cut into thin strips, not just battens) and fresh ginger. Prepare sauce, a mixture of light soy, shaoxin wine and a bit of shaved palm sugar. This time, I also added a tiny bit of fish sauce, it's not Cantonese, but oh well.
Drain all liquid and take away the ginger slices that steamed with the fish.
Pile the freshly juvienned spring onion and ginger over the fish, and pour in the sauce. Heat up some canola oil in pan (or wok, it doesn't really matter as the fish is not going back) until smoking and pour all over the spring onion and ginger (that's on top of the fish).
Serve with steamed rice and Asian greens.