Render the guanciale in a cold pan on low heat until crispy, remove and set aside, keeping the fat in the pan
Add the red onion to the guanciale fat and cook for a couple of minutes
Cook your pasta in UNSALTED water
Add a ladle of pasta water to the pan with the onion
Off the heat, add the pasta and toss with Pecorino, Parmigiano and cracked pepper
Return the guanciale, keep tossing until glossy and creamy
Serve immediately
