Cream sugar and butter together. Mix in eggs and vanilla to butter. Mix flour, baking soda, and salt in a bowl. Add to butter in three parts. Add chocolate chips and walnuts. Mix until thoroughly ...
In a 6-inch sauté pan, add cooking oil over high heat. Season black cod with salt and pepper on both sides, then sear presentation side down. Add remaining 2 tablespoons of butter, letting it brown.