Just an FYI, Black Cod is not Cod at all. They are not the same species. Black Cod is more correctly called Sablefish. Supposedly "Black Cod" is a nickname fisherman gave it because the fish kind of looks like Cod. Cod is relatively lean, mild flavored, with large white flakes, where Black Cod (Sablefish) has a creamy colored flesh, and a rich buttery flavor and texture. It is a high fat fish, with ultra-high Omega-3 oil content. Black Cod in my book is #1 of ALL fish. It is the standard by which all other fish shall be judged. (Just my opinion ;D) It has gotten very expensive in recent years. And is considered sustainable. Luckily I bought 10 pounds of filets from FishEx when it was on sale for about $19/pound (a rare price). I still have 5 pounds left. It is one of the top fish for smoking because of it's fat content on non-fishy flavor, but I have not smoked any yet. It's so expensive that I only eat it on special occasions. I usually stick to smoking salmon.
Looks like they used just plain ol Cod in the miso-poached video, but even just plain Cod would be elevated with a miso marinade. I actually use a recipe made famous by Nobu Matsuhisa. You can find his recipe all over the internet by searching "Nobu Miso Marinated Black Cod". Here is a similar recipe, with my own twist, which I think is even a little bit better than Nobu's...if I may say so myself.
Miso Marinated Black Cod
1/4 cup sake
1/4 cup mirin
1/4 cup white sugar
2 Tablespoons brown sugar
3/4 cup white miso paste
1 Tablespoon finely grated fresh ginger
1/2 Tablespoon sesame oil
In a sauce pan, place sake and mirin and bring to a boil for about 20 seconds to burn off alcohol. Lower heat and add miso paste. Stir with wooden spoon and cook on low heat until dissolved. Turn heat up to high and add sugars, ginger and sesame oil and stir constantly until sugar dissolves. Add some water if it becomes too thick. It should be a little softer than peanut butter. Remove from heat and let cool to room temperature. After marinade is cool, pat fish dry and coat with marinade, covering all surfaces. (You will not use all of the marinade, just enough to coat well. You can store the remaining marinade in the refrigerator almost forever.) Marinate in a zip-lock bag or non-reactive baking dish for 2-3 days in refrigerator. (Yikes, yes, 2-3 days).
Before cooking, remove excess marinade, but do not rinse. Place fish on lined baking sheet skin side down in a broiler for 5 minutes. Flip fish to skin side and cook for another 5 minutes. OR, cook in a regular oven at 375°– 400° for 7 minutes each side, or until desired doneness and caramelization. Can also pan-fry. Grilling is difficult because of the sugars in the marinade burning, potential sticking, and the fish falling apart easily. For sous vide, follow basic fish time and temp guidelines. Hitting it with a torch or searzall to caramelize the surface sugars leftover from the marinade would be ideal.
