Step 1

First, sprinkle the fish fillets with a pinch of salt on both sides and leave for 10 minutes.

Step 2

Cut the fresh ginger into 2mm thick slices.

Step 3

After 10 minutes, cut a cross or 2-3 diagonal lines on the skin. (If you're using a whole fish, cut both sides.)

Step 4

Take two bowls, fill one with freshly boiled water and the other with ice cold water.

Step 5

Swill the fish in the boiling water for 5 seconds, then transfer to the ice water. Remove the fish and dry with a paper towel.

Step 6

Pour 150ml water, 150ml sake, 50ml of mirin and 30g of sugar into a pan.

Step 7

Turn the heat on medium and stir.

Step 8

Once the sugar is dissolved, add the fish and ginger slices.

Step 9

Place your drop lid (instructions in post) on top of the fish and simmer for 3 minutes.

Step 10

Peel back the drop lid and pour 1 tbsp of soy sauce over the fish, spoon the liquid in the pan over the fish. Once the soy sauce is incorporated into the rest of the sauce, repeat this process twice more. (3 tbsp of soy sauce in total.)

Step 11

Return the drop lid to it's original position and simmer for 10 minutes.

Step 12

Cut the Japanese mustard spinach into 5cm (2 inch) pieces and bring a small pot of water to the boil.

Step 13

Add Japanese mustard spinach to the boiling water and boil until softened. (About 1 minute)

Step 14

Continue to spoon the sauce over the fish until the liquid is reduced to one third.

Step 15

Serve the fish fillets up on a plate, top with ginger and pour a few tablespoons of leftover sauce over the top. Place the Japanese mustard spinach on the side.

Step 16

Enjoy this dish served with rice.