Boil water in a pot and cook 100 g spaghetti according to package instructions until al dente.

Drain the pasta, reserving a small cup of pasta water.

In a bowl, combine the juice and zest of 1 medium lemon, minced garlic, and chopped parsley.

Toss the hot pasta with the lemon mixture and 50 g grated Parmesan cheese, adding reserved pasta water as needed to create a creamy sauce.