To prepare the lemon spaghetti, start by bringing a large pot of water to a boil for the pasta and salt it once boiling. Separate the basil leaves from their stems. In a large skillet, heat half of the olive oil together with the basil stems.
Using a vegetable peeler, shave wide strips of zest from the lemons, taking care not to remove the bitter white pith. Add the lemon zest strips and the anchovies in oil to the skillet. Cook over medium-low heat for about 3 minutes until the anchovies melt.
In the meantime, drop the spaghetti into the boiling water and cook for only half of the package time. Pour the lemon juice into the skillet and let the flavors meld for another 3 minutes of cooking, then remove and discard the basil stems and lemon peel strips from the pan.
Meanwhile, prepare the cheese cream: finely grate the Pecorino Romano cheese, then gradually whisk in hot pasta water until you obtain a smooth and lump-free cream.
Drain the half-cooked spaghetti and transfer it directly to the skillet. Finish cooking the pasta in the pan, adding one ladle of hot pasta water at a time while tossing and stirring constantly, as you would for a risotto.
Once the pasta is cooked al dente, turn off the heat to emulsify (mantecare): add the remaining olive oil, a generous grating of fresh lemon zest, and the basil leaves.
Stir well, then pour in the Pecorino cream. Toss vigorously until thoroughly blended and creamy, adding a splash of pasta cooking water if needed to adjust the consistency.
Plate the pasta and finish each serving with a few small fresh basil leaves and freshly ground black pepper. Your lemon spaghetti is ready to serve!
