Bring a large stockpot of water to a vigorous boil. Add salt generously—approximately 2 tablespoons per 500 grams of pasta—so the water resembles the salinity of seawater.
In a mixing bowl, whisk the eggs thoroughly until completely smooth. Fold in the grated cheese and a liberal dose of freshly ground black pepper to form a thick, paste-like consistency. Set aside.
Place the diced guanciale into a cold skillet without adding oil. Turn the heat to medium and allow the fat to render slowly. Cook for 5 to 7 minutes until the edges are crisp and golden but not overly crunchy. Remove from heat. With a slotted spoon, transfer the guanciale to a plate and retain around 2 tablespoons of the rendered fat in the skillet.
Add your pasta to the boiling water and cook until it reaches a firm, al dente texture, following the time on the package. Before draining, reserve half a cup of the starchy cooking water.
Immediately transfer the drained pasta to the skillet containing the warm guanciale fat. Toss well to coat the strands evenly. Remove the skillet from any heat source entirely to prevent the eggs from cooking too quickly.
Gradually add the egg-cheese mixture to the pasta, mixing rapidly with tongs or stirring briskly to form a smooth, glossy sauce. Add a small amount of the reserved pasta water as needed to achieve a creamy consistency that coats the pasta evenly.
Stir the cooked guanciale into the pasta, setting aside a few crisp pieces for final garnishing. Serve straightaway, topping each plate with an extra sprinkle of cheese and a final grind of black pepper.