Bring a large pot of generously salted water to a rolling boil.

Finely grate the zest from both lemons, then squeeze the lemons to collect the juice.

Dice the blast-chilled tuna into small bite-size cubes.

Cook the linguine in the boiling water until al dente, following the package timing.

Reserve 120 ml of pasta cooking water, then drain the linguine.

Whisk the ricotta cheese with lemon juice, lemon zest, salt, black pepper, and olive oil until smooth.

Warm the olive oil in a large skillet over medium-high heat, then sear the tuna cubes for 30 to 60 seconds.

Add the drained linguine and ricotta mixture to the skillet, then toss to coat the pasta.

Add reserved pasta cooking water a little at a time, then toss until the sauce becomes glossy and creamy.

Season with additional salt and black pepper, then serve the creamy lemon tuna linguine immediately.