In a stainless saucepan, heat 2 tablespoons of clarified butter to smoking point.
Add orange peels and stir vigorously, allowing peels to almost burn on edges and cook through.
Add juice, star anise, and rice wine vinegar. Reduce by 3/4 or until "syrupy."
One half hour before you are ready to serve, whisk in a stick and one half of the sweet butter. Season to taste.
For the cod
Brush one side of the board with 2 tablespoons of the olive oil and let it sit overnight
Arrange a rack in the center of the oven and preheat the oven to 450 degrees F. Place a large rimmed baking sheet underneath the center rack to catch the cod drippings.
Place the cod fillets on the plank. Tuck a sprig of tarragon and some chives under each fillet. Lightly brush the cod with the remaining 2 tablespoons of olive oil and sprinkle with salt and pepper.
Place the board in the oven for 10 minutes. To make sure the fish is cooked properly, lightly brush the cod with the remaining 2 tablespoons olive oil and sprinkle with salt and pepper.
Place the board in the oven for 10 minutes. To make sure the fish is cooked properly, lightly squeeze the fillet with your finger; it should fell firm and just start to give way. Carefully remove the board from the oven. With a metal spatula, transfer the cod fillets to warm plates
Whisk together the sauce briefly, recombine and spoon some of it over each fillet. Serve at once.