Recipe of the week: tuna tataki with salsa verde

This is a classic tataki dish using yellowfin tuna loin. Tuna is a complicated matter, and I personally took the ethical decision not to eat or serve bluefin tuna back in the late 1990s when it became very apparent what an enormous pressure this mighty fish had been under for at least four decades.

Bluefin tuna is the king of fish in Japanese food, in particular for sushi and sashimi, famed for its smooth texture and the fatty part named toro. However, wild stock is on the brink of collapse and currently the outlook is grim.

The best alternative is yellowfin from the eastern Pacific, where stock is healthy and fishing is well-managed and monitored. To me, yellowfin tuna is equally tasty and actually easier to work with as it comes in a firm, even loin, not dissimilar to a good piece of beef.

I recommend eating tuna in moderation, but really go to town when you do: source the finest quality from the fish market or a reputable fishmonger.

Serves 4-6
700g-800g tuna loin, middle cut
150ml extra virgin olive oil, plus a little extra to coat the fish
Salt and freshly ground black pepper
2g dried wakame seaweed
1tsp wasabi powder
½ bunch flat leaf parsley, finely chopped
½ clove of garlic, finely chopped
1tsp Dijon mustard
2tbs mirin
40g drained capers, finely chopped
Green beans
Sugar snap peas
Mustard miso

Prepare the tuna loin on a chopping board: cut away the sinew part of the loin, which constitutes the belly flap on a yellowfin tuna (store this in the fridge and scrape out the tuna with a spoon when needed, to use in another recipe).

Divide the loin into rectangular logs about 2.5cm in diameter; you should get between four and six blocks out of the loin. Pour a little olive oil into a shallow tray and season with salt and pepper. Roll the loins in the oil, ensuring they are well coated, and set aside in the fridge, covered.

Now for the salsa verde. Dilute the wakame in 500ml cold water and leave for 10 minutes. Mix the wasabi powder with a little water to make a paste. In a bowl, combine the parsley, garlic, wasabi paste, mustard, mirin, capers and olive oil. Drain and chop the wakame and add to the bowl, then set aside.

Start the robata grill. When it is ready, grill the tuna on a wire rack for less than a minute on each side, so it is evenly seared. With a very sharp cook's knife or sashimi knife, slice the tuna into 5mm-thick slices, starting from the heel of the knife and pulling the knife towards yourself in one even movement, to avoid sawing through the protein and tearing the flesh.

Arrange the tuna slices along the length of the serving dish, overlapping one another. Spoon a little salsa verde on top and serve with green beans and sugar snap peas with mustard miso.

• Recipe taken from Robata: Japanese Home Grilling by Silla Bjerrum

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