In a large pot, bring salted water to a boil.
Add the spaghetti and cook until al dente.
Reserve some cooking water and then drain it.
While pasta is cooking, heat a large skillet over medium heat.
Add guanciale and sauté for around 3 minutes.Turn off the heat.
In a bowl, beat the egg and the yolks with pecorino and a drizzle of pepper and stir.
Add the drained spaghetti to the skillet with guanciale and toss for a minute or so over medium heat.
Season with some fresh ground black pepper and immediately serve in warm plates/bowls.
Transfer into the bowl with the eggs/pecorino mixture, stirring until the egg sauce thickens.
Add some cooking water if the sauce is too thick or pecorino if it’s too liquid.