Pan-seared tuna steaks with maple and mustard

🧊 Cold tuna. This is the whole game

Out of the fridge at the last second, straight into the marinade, straight into the pan. Tuna that has been sitting on the counter is already halfway cooked before it touches heat, and you lose the cool centre in about ten seconds. Everything else in this recipe is negotiable. This is not.

🐟 Sushi-grade, or make something else tonight

Ask the fish counter directly. In the United States you will usually see it sold as ahi, yellowfin or bluefin, and the label you want says sushi grade or sashimi grade. Regular case tuna will not work here, because a 90-second sear does nothing to hide a mediocre piece of fish: the middle reads metallic and the texture goes soft. You are buying two steaks. Buy the good ones. Frozen is fine too, as long as it was frozen at sea and you thaw it overnight in the fridge, never on the counter and never under running water.

🔥 Medium-high. Not wide open

Give the pan a splash of oil and about two minutes to come up. You want a heavy pan that actually holds its heat, and you want the oil shimmering and sliding, not smoking. Full blast sounds right and is wrong: the maple in the marinade burns before it caramelizes and you end up with a bitter crust on cold fish. Oil, not butter, for the sear. Butter has milk solids that scorch at this heat, and the tuna is out of the pan long before butter would give you anything back.

⏱️ Forty-five seconds a side, timer running

For a 250 g (9 oz) steak at 2 cm (3/4 in), that is 45 seconds and then it flips, and 45 seconds and then it comes out. Longer than that and the heat walks into the centre, which is where tuna turns dry and rubbery and there is no rescuing it. Thicker steak, closer to 3 cm (1 1/4 in), goes to about a minute a side. Thinner than 2 cm, go by colour instead of the clock and pull it the moment the seared band creeps past a few millimetres.

🌡️ Where the temperature should land

If you like numbers, an instant-read probe in the middle of a properly seared tuna steak will show somewhere around 46 to 52 °C (115 to 125 °F). That is rare, and it is what this recipe is built for. The food-safety number for fish is 63 °C (145 °F), which cooks the steak through and costs you every reason you bought sushi-grade tuna in the first place. Your call, but I would rather eat something else than eat this well done.

⚗️ Ten minutes in the marinade, and that is a ceiling

The acid in the Dijon starts curing the surface the way lime does in a ceviche. Past ten minutes the outside of the steak goes pale grey and loses the look you were after. Five to ten minutes, then cook.

🔪 Cut it on the bias

About a centimetre thick, on the diagonal, across the grain. Wider pieces, softer bite, and the whole rosé centre faces up on the plate instead of hiding. It takes four seconds and it is the difference between a piece of fish and something that looks like it came out of a restaurant.

🧂 The orange-coriander salt, and what to do without it

I have been using a flavoured sea salt from Les Sœurs en Vrac, a small Quebec outfit, for years on this recipe. Orange zest and coriander seed against maple and mustard is the part people ask me about. If you cannot get it, mix flaky salt with dried orange zest and ground coriander and you are most of the way there. Try the real one once anyway.

✅ What to serve with a seared tuna steak

Something green and sharp is the obvious move, and my white balsamic arugula salad is the one I make most often, because the acid does the same job as a squeeze of lemon. When the tuna is the whole meal I put my grilled asparagus with miso and maple beside it and let the maple echo across the plate. If people are hungry, my quick sesame Chinese noodles turn this into a real dinner in the same half hour. And if you want the sesame version of the same fish, my tuna tataki with sesame crust is right there.