Scale the fish, and place the knife between the pectoral fin and gills and chop off the head.

Gut the fish, and rinse the inside and fillet it. For those who dislike the small bones, use fish bone tweezers to extract the bones.

Make a decorative crisscross cut not only for the appearance, but also to allow the flavors to absorb well.

Chop the leeks into 3-cm lengths, and slowly grill over low heat until brown.

Chop the eggplant into eight equal pieces, and soak them in salt water. Wipe the excess water, then deep-fry them in oil for 3-4 minutes.

Combine the miso and mirin. A blend of different types of miso enhances the flavor.

Blanch the mackerel to remove the odor: place the mackerel in boiling water for 5 seconds, drain, and transfer to chilled water. Rinse off any of the slipperiness in the cold water.

Alternatively, you could also pan-fry the fish in a frying pan. This will not only remove their odor, but will add a nice aroma.

Pour the sake into the frying pan, heat the pan, and evaporate the alcohol. Then, add the sugar and water.

Once it comes to a boil again, add the mackerel, cover with a drop lid, and simmer for 3 minutes over low heat to let the flavors of the sauce fully cook into the fish.

After 3 minutes, with the heat still on medium, pour in 2/3 of the miso and mirin sauce, and simmer for 5 minutes.

After 5 minutes, add the grilled leeks, and add the remaining 1/3 of the miso. Spoon the sauce over the fish and simmer until the sauce thickens. Be careful not to simmer it for too long!

Use a spatula to transfer the fish to a plate, then drizzle on the sauce. Arrange the leeks and eggplant beside it, and garnish with the shredded white leek.