Senba-jiru (Salted Mackerel and Daikon Clear Soup)

Ask a fishmonger to remove mackerel guts and gills and separate flesh, head, and backbone.

Rinse quickly in cold water, blot dry, and cut flesh to 2cm widths.

Sprinkle all mackerel parts evenly with 15g curing salt, set on a rack, and refrigerate at 4C or below for 1 hour.

Discard liquid and rinse surface salt quickly with cold water.

Spread head, bones, and flesh in a sieve and pour 1500ml boiling water evenly over them.

Dip in cold water for 10 seconds, remove remaining blood and scales, and drain.

Peel daikon and cut to strips 5cm long and 7mm thick; blanch 3 minutes and drain.

Cut both onions to 3cm, shred along the grain, soak in cold water 5 minutes, and drain.

Combine 1000ml water, 10g kombu, and mackerel head and bones over high heat.

At boiling, remove kombu, skim and simmer 10 minutes, then strain through a sieve lined with paper towel.

Return clear broth to a clean pot and add daikon, mackerel flesh, and serving-size backbone pieces.

Add sake, light soy, and half the final salt and simmer 6 to 8 minutes until fish reaches 63C.

Taste and add only as much remaining salt as needed.

Divide daikon and fish, pour in broth, squeeze grated ginger through cloth for a few drops per bowl, and top with onion shreds and yuzu peel.