Seared Tuna Steaks with Sesame and Greens

There is one rule with tuna and it is this: a tuna steak cooked all the way through is a waste of a tuna steak. It goes grey, it goes dry, and it tastes like the tin. Ninety seconds a side on a screaming hot pan, still deep pink in the middle, and it is one of the best things you can put on a plate in five minutes.

It is also the leanest serious protein in the shop. Forty-six grams a serve for 270 calories, which is why it turns up in every meal-prep container in Canberra.

What you need

• 4 tuna steaks, about 180 g each and at least 2.5 cm thick
• 1 tbsp sesame oil
• 1 tbsp sesame seeds (white, black, or both)
• 2 tbsp soy sauce
• 1 tbsp grated fresh ginger
• 400 g Asian greens — bok choy, choy sum or gai lan
• Wasabi and lemon, to serve

Thickness matters more than weight. Ask for steaks cut at least 2.5 cm thick — a thin steak has no middle left to keep pink, and it will be cooked through before the outside has any colour.

How to cook it

1. Take the fish out of the fridge twenty minutes early. A fridge-cold steak cooks unevenly, and with a ninety-second sear there is no time to fix that.
2. Season and coat. Pat dry, brush lightly with sesame oil, press the sesame seeds onto both flat faces, season with pepper.
3. Get the pan hotter than feels sensible. Heavy pan, no oil in the pan itself — the oil is on the fish. You want it just short of smoking.
4. Ninety seconds. Turn. Ninety seconds. Then straight onto a board. Don't press it, don't move it, don't check it.
5. Greens in the same pan. Ginger, greens, a splash of water, lid on for two minutes. Soy sauce off the heat.
6. Slice against the grain into finger-thick pieces so the pink centre shows. Wasabi and lemon on the side.

Making it work for you

If pink isn't for you: go three minutes a side and accept it will be firmer — or use swordfish or marlin instead, which are built for cooking through and stay moist doing it.

Meal prep: seared and sliced, this keeps two days in the fridge and is meant to be eaten cold. Over rice with the greens is a genuinely good lunch.

Watching sodium: the 2 tbsp of soy is about 1,800 mg across the dish. Halve it, or swap to a salt-reduced soy.