Marinating mackerel in soy sauce helps to mellow out its strong flavor and adds a savory and umami taste. Grill or pan-fry the marinated mackerel until it is cooked through and serve with a side of steamed vegetables and a drizzle of sesame oil for a simple and nutritious dinner. The rich and oily texture of the mackerel pairs well with the soy sauce marinade, creating a delicious and satisfying meal.