Because of the saltiness of the meat and the cheese, it is not recommended to salt the water for the pasta.
5 ounces guanciale or pancetta, cubed
1½ teaspoons coarsely ground pepper, divided
6 ounces pasta (I used mezzi rigatoni)
¾ cup grated Pecorino Romano cheese, divided, about 2½ ounces (and more for passing)
Start a large pot of water on the stove to boil. At the same time, fry the diced meat in a large fry pan over medium heat until the edges are a bit crispy. Remove meat with a slotted spoon and set aside. Do not wipe out pan.
After the water has come to a boil, cook the pasta until about halfway done - you want the pasta to still be firm (the pasta will continue to cook later in the recipe). If you are using spaghetti, for instance, this will only take a couple of minutes. Add about ¾ cup of the pasta water and the ground pepper to the skillet with the fat from the meat and cook over medium high heat, whisking, to thicken, for about a minute. Remove pasta with a spider, tongs or some other kind of strainer and place in the skillet. Vigorously stir the pasta with the sauce and add more pasta water if it's too dry. Add ½ cup of the cheese and stir, over the medium heat. The cheese will melt into the sauce - add more hot pasta water if you have to. Keep cooking and stirring until the sauce is creamy and the pasta is cooked, but still al dente. Add the guanciale or pancetta and stir to blend.
Transfer to a serving dish, sprinkle with more cheese (and more pepper if you like) and serve. The pasta should be well coated with cheese and pepper, but there shouldn't be a liquid sauce to this dish - if there is, you used too much pasta water