Black Cod with Clam and Tarragon Sauce

I was wandering in my neighbourhood the other day and came across 2 delicious tranches of black cod. Fresh in that day. Marvellous. I love fish, and there's really nothing more delicious and simpler than an ingot of fresh fish with an easy sauce.

I really like the taste of tarragon with seafood, so I bought a bunch of leaves and a small bottle of clam juice to give the sauce some oomph. Off we go. This served me and the wife:

half a head of savoy cabbage, shredded finely
1-2 tbsp butter
3 or 4 cremini mushrooms
2 thick slices of black cod
2 tbsps olive oil
sea salt and white pepper
2 tbsp clam juice
2 tbsps heavy cream
chiffonade of tarragon
dash of lemon juice/white wine vinegar to taste

Finely shred the cabbage and cook in half the butter until wilted. Season and keep warm. Quarter the mushrooms and fry in remaining butter until coloured, about 6 mins and keep warm. Heat olive oil in a non-stick pan until it shimmers. Season cod's skin-side with salt and pepper and add to the pan, skin side down. Season the other side of the fish. Fry for about 8 mins skin side down, or until it gets some colour at the edges. Turn over, cook for another 2-3 mins, depending in the thickness of the fish and transfer it to a plate and keep warm in the oven. Add the clam juice to the non-stick pan which the fish has cooked in, and scrape up any brown fishy bits from the bottom and bring in to a bubble. Add the cream and continue to cook over a high heat until slightly reduced. Add the finely chopped tarragon. Add lemon juice to taste.

To assemble, put some of the cabbage in the middle of a warm plate, rest the fish on top of that, spoon the sauce around the plate and garnish with the meaty creminis.

*To follow this, I made an impromptu dessert - Chocolate/Orange gratin with whipped cream (I know, more cream.) I segmented a large orange and layered it with segments of Terry's Chocolate Orange in between, covered with smashed pecan shortbread biscuits and baked in a 375 oven for 20 mins. I let it cool and wolfed it down messily with some chilled whipped cream. Good Lord, it was delicious. (Thank you, Jacques Pepin.)