In a large nonstick pan, heat the olive oil, and then add the guanciale and garlic. Cook for about 10 minutes, making sure that the meat does not get too crunchy and the garlic does not burn. Cook's Note: If you see that the garlic is browning too fast, remove it from the pan, finish the pork, and then add it again to the sauce.
When the guanciale and the garlic are nice and golden brown, add the sage.
Bring a large pot of salted water to a boil, add the pasta to the water, and cook it about 2 minutes less than indicated on the box. Strain the pasta and add it to the saucepan over a medium-high heat, toss it around for a few seconds, then add the grated Pecorino, toss for one minute.
Garnish with some grated Pecorino, a drop of extra-virgin olive oil, and some ground black pepper. Serve with a bottle of robust red wine.
Since you probably rinsed it before, make sure the herbs are well dry; otherwise you'll end up bathing yourself in a sprinkle of boiling oil.