Finely grate the pecorino cheese and place two-thirds in a large bowl. Add freshly ground black pepper.
Cook spaghetti in a large pot of lightly salted boiling water according to package instructions or until al dente, approx. 8 min. Add spaghetti and some pasta water to the bowl of pecorino and pepper. Toss with tweezers or tongs, until cheese melts and creates a creamy sauce that coats the pasta. If necessary, add some more pasta water for the creamiest texture. Season to taste with more pepper and salt, if needed. Serve immediately and enjoy!