Mackerel simmered in soy and ginger (Sakana no nitsuke)

1. Cut the mackerel fillets into 4 pieces, score a cross in the skin, then dip briefly into boiling water and rinse under cold water – this removes the fishy smell.

2. Cut the ginger into thin matchsticks and the spring onions into 4 cm lengths.

3. In a wide, shallow pan, bring the water, sake, soy sauce, mirin and sugar to the boil and add half the ginger.

4. Lay the fish skin side up side by side in the boiling liquid and cover with a circle of baking paper cut to fit the pan, so the liquid covers it all over.

5. Simmer over medium heat for 10-12 minutes, basting a few times; add the spring onion alongside for the last 3 minutes.

6. Serve the fish with the reduced liquid, the onion and the remaining raw ginger strips, with rice.

Tip: Nitsuke is a cornerstone of Japanese fish cooking: a short simmer in a little flavourful liquid. The paper lid (otoshibuta) is the secret – even a small amount of liquid wraps the fish and it doesn't fall apart.