Bring a large pot of heavily salted water to a rolling boil.
Add the pasta and cook for the duration specified on the packaging until it reaches an al dente texture.
Reserve 120ml of the starchy pasta cooking water before draining the pasta through a colander.
Return the pasta to the warm pot and add the drained tuna, basil pesto, cherry tomatoes, and lemon juice.
Toss the ingredients thoroughly, gradually adding the reserved pasta water to emulsify the sauce and coat the pasta evenly.
Season with salt and black pepper according to preference.
Portion the pasta into bowls and garnish with grated Parmesan cheese and fresh basil leaves.