Use scissors to remove the fins on either side of the fish.
Lay the fish on a flat work surface and hold it by the tail with one hand. Gripping a knife with your other hand, scrape the scales off the fish starting working from the tail towards the head.
Once the fish is perfectly descaled, rinse it under cold running water.
Using a sharp knife, make a deep cup in the fish from the head to the middle of the belly.
Then, place your fingers in the stomach cavity and carefully remove the guts. wash the fish under cold running water, both inside and out.
Working parallel to the work surface, insert your knife in the flesh of the fish, just behind the head and above the spinal bone.
Carefully move your knife back and forth in a sawing motion, moving it along the spine down towards the tail. Finish by detaching the fillet. Repeat on the opposite side.
Clean up the fillets by removing any membranes and the parts with blood. Rinse the fillets one last time before cooking.