Saikyoyaki is a type of grilled fish dish from Japan that is cooked with saikyo miso, which is a kind of sweet and mild miso paste. Saikyo miso is made from soybeans and rice that has been fermented, which means it has been left to sit and grow flavors over time. This miso paste is then used to marinate fish, usually a lighter and more delicate fish like black cod or sea bass.
The marinade is allowed to soak into the fish for a period of time, which can vary depending on the recipe used. Once the marinating process is completed, the fish is then grilled or broiled until it is cooked through and has a flavorful outside layer. The end result is a very tender and flavorful fish that is both sweet and savory, with a slightly caramelized exterior.
Saikyoyaki is often served as a main dish alongside rice and vegetables, or it can be included as a part of a larger meal. It is a popular dish in Japan and is often enjoyed by people of all ages due to its mild flavor and soft texture.