Cook the pasta in boiling salted water until al dente, drain and reserve approx. 100 ml of the cooking water.
Heat the oil in a frying pan, briefly sauté the garlic, add the agretti and fry for approx. 3 mins., season with salt. Add the reserved cooking water, lemon zest and juice.
Stir in the pasta and heat gently. Sprinkle with parmesan, season.