Render the guanciale. Add the guanciale (or pancetta) to a large skillet and cook it over medium heat for about 10 minutes until it becomes crispy and golden in color. You really want to be patient when doing this and allow the guanciale to fully render in its fat for the most flavor. Then once it’s nice and crispy, transfer the guanciale to a plate, but leave the fat in the skillet. You'll need about 2 tablespoons of fat, if it's too much, scoop some out.
Boil the pasta. While the guanciale is rendering in the skillet, bring a large pot of salted water to a boil. Then add the rigatoni and cook till it’s al dente, which is typically about a minute less than the package directions suggest. When the rigatoni is done cooking, reserve 2 cups of the starchy pasta cooking water, and then drain the pasta.
Start the sauce. Add the freshly ground black pepper to the rendered guanciale fat in the skillet and cook for about a minute. Then add just 1 cup of the reserved pasta water, turn the heat on to high, and bring the mixture to a boil continuing to cook until it reduces by about a half.
Add the pasta. Add the cooked rigatoni to the skillet. Then toss the pasta together with the rendered fat and pasta water mixture with a wooden spoon adding more of the reserved pasta water if necessary. The rigatoni should be thoroughly coated in the sauce and not dry.
Add half of the cheese. Stir half of the finely grated Pecorino Romano cheese into the pasta until it’s fully incorporated into the sauce. You want the sauce to be both creamy and look glossy.
Add the guanciale. Add the crispy guanciale into the pasta and toss to combine.
Finish with cheese and serve. Garnish with the remaining Pecorino cheese and more freshly ground black pepper. Then serve hot and enjoy!