Tuna and Tomato Spaghettini

Fill a large pot with water, add 1 tbsp salt and bring it to a boil over high heat, about 10 minutes. Chop the onion, mince the garlic and cut the Roma tomatoes while you wait.

Warm 2 tbsp of the olive oil in a large skillet over medium heat. Add the onion and a pinch of salt and cook 5 minutes, stirring now and then, until soft and translucent.

Stir in the garlic, oregano and chili flakes and cook 1 minute, until fragrant. Pour in the diced tomatoes with their juice and simmer over medium heat 10 minutes, until the sauce thickens and a spoon drawn through it leaves a clear trail.

Tip: Keep it at a lively bubble, not a hard boil, so the sauce thickens without catching on the bottom.

Meanwhile, boil the spaghettini 7 to 8 minutes, until tender with a slight bite in the centre. Scoop out 1 cup of the pasta water, then drain the pasta in a colander.

Add the Roma tomatoes to the sauce and cook 3 minutes over medium heat, until warmed and just softened at the edges but still holding their shape. Season with pepper and a little salt.

Add the drained spaghettini and 1/2 cup of the pasta water to the skillet and toss with tongs over medium heat for 2 minutes, until the sauce coats every strand; add a splash more water if it looks dry.

Take the pan off the heat. Break the tuna into large flakes over the pasta, drizzle with the last 1 tbsp olive oil and fold gently for 30 seconds, just until the tuna is warm.

Tip: Fold rather than stir hard, or the tuna shreds and disappears into the sauce.

Twirl the pasta into warm bowls, spoon over any tuna and tomato left in the pan and finish with the finely grated Grana Padano.

Tip: Leftovers keep 3 days in the fridge; reheat in a pan with a splash of water and add fresh cheese.