Use a sharp knife to cut around the bones running along the outside edge of the turbot.
Holding the knife at an angle, separate the fillet by running the knife between the flesh and the bones.
Continue along the backbone to the end of the tail and detach the fillet from the body of the fish.
Repeat this process to remove the fillet on the lower half of the fish and on the opposite side. You should end up with four fillets.
Clean the fillets by removing any membranes and any remaining blood. Also clean up the edges of the fillets, removing any small bones that were left.
Once the turbot has been filleted and rinsed, cook it as you desire.