Gather your ingredients. Trim your cod to make some pieces which are a bit on the thicker side and uniform.
Salt both sides of the fish. Cover and place in the fridge for 1+ hours.
When ready to start cooking, put the oil in a pan. Stainless works better than non-stick for this type of cook.
Warm the oil over high heat. Ensure the bottom of the pan is fully coated in oil.
While the oil heats, use a paper towel to wipe all excess moisture off the fish.
Right when the oil gets close to smoking, carefully place each piece of fish in the pan.
Once the fish has formed a nice crust (maybe 5 minutes or so), drop the heat to medium. Add the butter.
Be sure to keep the heat low enough to avoid burning the butter, but hot enough to keep cooking the fish. Constantly baste the fish with the butter. When the fish reaches your desired internal temp (145 deg for me), remove and plate.
For plating I put down the sauce first.
Then made a bed of asparagus.
And lastly placed the cod and garnished with capers and chives. Enjoy!