Searing the tuna steaks – just a little, hot and fast
Set a skillet pan big enough to hold all four steaks over a high heat with 2 tablespoons olive oil.
As the oil is heating, sprinkle a level teaspoon of the ground sea salt over both sides of the tuna steaks – that’s one level teaspoon for all four steaks – not a teaspoon for each one.
As soon as the oil starts smoking, cut the heat back to medium-high and add the tuna steaks. Let them sizzle away for two minutes, then turn them and cook for another two minutes. Turn off the heat and let the steaks sit in the skillet whilst you make the sauce.
Cooking the tuna’s sauce
Heat three level tablespoons of olive oil in a medium-sized pot (that will take a lid) over medium heat. Add the sliced strips of red bell pepper, stir well to coat them with the olive oil and turn the heat down to low-medium. Cover the pot with its lid. The peppers need to soften, but not brown at all. So, keep them slowly cooking for 10 minutes with some regular stirring.
Add the chopped cherry tomatoes, the sliced garlic, the sugar, and ground sea salt. Cook for another five minutes on that low-medium heat - stirring now and then - until the cherry tomatoes lose most of their body.
Now add all the sauce’s remaining ingredients (including those chili peppers), stir it all together, and let the sauce gently simmer for another 10 minutes. Turn off the heat. Done.
Cooking the spinach
Melt the butter in a medium-size pot over a low heat and add the sliced garlic and sea salt. Stir the pot and let the garlic release its flavor into the butter – about 3 minutes over a stirred low heat. The garlic must not brown.
Add all of the spinach. It’ll be a bit of crush to get it into the pot – that’s ideal - pile it in and put the lid on. After two minutes, stir the spinach so that it all picks up a coating of the buttery garlic. Put the lid back on and let the spinach cook for another two minutes. Then stir the spinach again, put the lid back and let it cook for another two minutes. Turn off the heat and keep the lid on so the spinach retains its heat as you finish cooking the tuna in the sauce.
Bringing it all together
Put the skillet with the seared, partly cooked tuna steaks onto a medium heat and pour the sauce over them. Lift the steaks a little so that they sit in the surrounding sauce as it heats. As soon as the sauce starts to bubble, turn the heat to low and let the steaks finish their cooking for about six minutes at a very gentle simmer in the sauce. They’ll then be ready to serve – straight from the skillet, with the emerald green spinach presented alongside.
Tuna freezes really well because of its ultra-low fat content. So, no need to necessarily buy fresh steaks – I certainly didn’t. I bought the lowest-priced frozen option from a trusted fishmonger where I have shopped for over twenty years. No complaints…On the chili peppers: This is not supposed to be an intensely fiery sauce, but you do want it to have some convincing chili-evidence. The tuna’s strong flavor really is complemented by the chili’s power. Use the chilies accordingly (and to your heat tolerance.)On the sherry: The same amount of fortified Marsala wine would probably be more traditional, but sherry is a lot easier to come by… So that’s what I used.As for drinks: I’d go for a full-bodied fruity rosé, chilled but not icy cold. White wine lovers should perhaps consider a big, wooded chardonnay.Also a grand variant on this dish for four is to halve the quantity of spinach and tuna steaks but cook everything the same way – just break the steaks into bite-size chunks as they end their cooking in the sauce and stir in the cooked spinach at the last minute. Serve over linguine and top with parmesan. Fab!