Cook the pasta in a large saucepan of salted boiling water for 8–10 minutes, or according to packet instructions, until al dente.
Drain the pasta, reserving half a ladleful of the cooking water. Return the pasta to the pan and place over a low heat. Add all the remaining ingredients, season generously with pepper and stir until the butter has melted and the pasta is evenly coated. If it looks slightly dry, add some of the reserved cooking water. Serve immediately.