The Preparation
Bring a large pot of well-salted water to a boil.
Cook guanciale or pancetta in a skillet over medium heat until rendered and crispy. Remove from heat.
Whisk eggs, egg yolks, Pecorino Romano, and Parmigiano-Reggiano together in a bowl. Season with black pepper.
Cook pasta until al dente, reserving at least 1 cup of pasta water before draining.
Add hot pasta to the skillet with the guanciale (off heat or on very low heat).
Pour egg and cheese mixture over pasta and toss quickly, adding pasta water a little at a time to create a creamy sauce.
The heat from the pasta cooks the eggs — do not put over high heat or eggs will scramble.
Serve immediately with extra Pecorino and cracked black pepper.
