Saba no Miso-ni (Simmered Mackerel with Ginger)

Place the soy sauce, mirin, sake, sugar, water, and sliced ginger into a small skillet or saucepan.

Bring the mixture to a boil over medium heat until the sugar dissolves.

Add the scored mackerel fillets to the pot, skin side up.

Cover with a drop-lid (otoshibuta) or pan lid, turn the heat down to low, and simmer until the fish is cooked through and tender, about 8–10 minutes.

Then 8 min of waiting

Remove the lid and gently spoon the simmering glaze over the mackerel repeatedly to coat the tops evenly.

Continue simmering until the liquid thickens into a glossy sauce, 2–3 minutes.

Transfer the mackerel fillets to serving plates and drizzle with the remaining pan sauce and ginger slices.