1 Bring a large pot of lightly salted water to a boil. Cook spaghetti in the boiling water, stirring occasionally until tender yet firm to the bite, about 10 minutes. Scoop out some of the cooking water and reserve. Drain spaghetti.
2 Heat oil in a large skillet over medium heat. Add garlic and pepper; cook and stir until fragrant, 1 to 2 minutes. Add spaghetti and Pecorino Romano cheese. Ladle in 1/2 cup of reserved cooking water; stir until cheese is melted, about 1 minute. Add more cooking water until sauce coats spaghetti, about 1 minute more.