Step 1

Bring a large pot of salted water to a boil; add the pasta and cook until al dente.

Step 2

Meanwhile, melt the butter in a heavy frying pan over medium heat. Add the pepper and cook, swirling the pan, until it begins to sizzle, about 1 minute. Set aside.

Step 3

When the pasta is al dente, use tongs to transfer it tothe frying pan and place the pan over low heat (keep the pot of pasta water nearby: you may need it). Add the Parmigiano and 1/2 cup of the pasta cooking water to the frying pan and, with tongs, immediately toss the pasta until the cheese melts; you want to keep everything moving so the cheese doesn’t sink to the bottom of the pan and start clumping. If a film of cheese begins to form on the bottom of your pan, reduce the heat and continue tossing. Add more pasta cooking water as necessary; the sauce should be creamy and emulsified and coat each strand of pasta.

Step 4

Remove from the heat, stir in the Pecorino, and toss to coat. Transfer to bowls and serve hot.