Bring a large pot of water to a rolling boil and season generously with Fine Salt; add the Rigatoni and cook until just shy of al dente (about 1–2 minutes less than package instructions), reserving 1–2 cups of the starchy cooking water before draining.
While the pasta cooks, cut the Guanciale into small matchsticks or dice so it renders evenly.
Place the guanciale in a cold skillet and set over medium heat; cook, stirring occasionally, until the fat has rendered and the pieces are crisp and golden, about 6–8 minutes. Reduce heat to low and keep the rendered fat in the pan.
Crack a generous amount of freshly ground Black Pepper into the skillet and toast briefly with the guanciale fat to release its aroma.
Add the drained rigatoni to the skillet and toss to coat in the fat; if the pan seems dry, add a few tablespoons of the reserved pasta water and toss over low heat to create a glossy emulsion. Repeat with more cooking water as needed to reach a silky consistency.
Remove the pan from heat and sprinkle in most of the finely grated Pecorino Romano, tossing vigorously so the cheese melts into the sauce and binds with the starchy water; add more pasta water or cheese to adjust thickness and salt to taste (remember guanciale and Pecorino are salty).
Serve immediately on warm plates, finishing each portion with extra grated Pecorino and another crack of black pepper for contrast.
