Clean and wash fish. Cut head, tail, and fins off. Cut fish into steaks.
Place fish in a bowl, add salt, cover with cold water and refrigerate for 2 hours. Remove, rinse and pat dry.
Sprinkle with pepper. Place flour in a shallow dish. Place each piece in flour to cover. Shake off any excess flour.
In a large frying pan, heat oil and butter. Place pieces of fish and sauté for a few minutes on each side on medium heat. Remove and place on a paper towel to soak up extra fat. If steaks are thick, finish in a 350°F / 180° C oven.
Serve immediately or keep in a warm oven until ready to serve.
