Cover a frying pan with aluminum foil.

Grate Daikon radish, and set aside.

Clean and fillet the fish or have your fish shop do it for you. Cut each fillet of mackerel in half. Sprinkle salt liberally on both sides of the fish.

Heat the frying pan at medium heat, and oil the surface of the aluminum foil lightly. Place the fish skin side down on the pan. Cook 4-5 minutes on each side, or until brown and cooked through.

Plate the fish, then add grated radish on the side, and pour some soy sauce on the radish if you want.