salted mackerel
Refers to mackerel that has been salted and often dried; a traditional preserved food.
I grilled and ate the salted mackerel my grandmother sent me.
この地方では、塩鱒を酒の肴にすることが多い。
In this region, salted mackerel is often served as a snack with alcohol.
Compound of 塩 (salt) and 鱒 (mackerel). The exact historical origin is uncertain, but it follows a common pattern for naming salted fish.