Cut the Guanciale into 0.5cm / 1/5" thick slices then into dices. If using Pancetta remove the skin and keep it for later then sliced like above and into batons.
Place guanciale in a cold non stick pan over medium high heat. Cook until golden and crispy. No oil needed – as the guanciale heats up, the fat will melt so it fries in its own fat.
Once fried, remove the Guanciale and place on top of absorbing paper. (KEEP THE FAT IN THE PAN TO THE SIDE).
Place eggs and yolks in a large bowl. Whisk to combine.
Whisk in the Pecorino and fresh ground black pepper.
Bring 4 litres (4 quarts) of water to the boil and season it well with salt. Add pasta and cook as per packet recommendation.
When pasta is about 3/4 cooked, scoop out 2 cups worth of pasta cooking water, finish cooking to al dente then drain the pasta.
Put the hot pasta into the pan and toss to coat in Guanciale fat.
Transfer the pasta and any residual fat in the pan into the bowl with the egg. Add 1/2 cup (125 ml) pasta cooking water.
Stir vigorously using long tweezers for 1 minute until the sauce transforms from watery to creamy and clings to the pasta strands!
Transfer into warm bowls. Serve immediately, garnished with a little extra Pecorino, and some freshly cracked black pepper.
That's about it time to eat, Buon Appétit!