Pasta Alla Gricia

In a large high-sided pan over medium-high heat, cook pancetta, stirring frequently, until deeply golden, 6 to 7 minutes. Remove from heat and, keeping the fat in the pan, use a slotted spoon to transfer guanciale to a plate. Add pepper to pan and stir to toast. Meanwhile, add water and salt to a medium-large pot and bring to a boil. Add pasta and cook, stirring to prevent sticking, until pliable, 2 to 3 minutes. Remove from heat. Return pan to medium-low heat. Add 1 ¾ cup pasta water to pan and swirl to combine. Add parcooked pasta and ½ cup of Pecorino and stir to coat evenly. Once Pecorino is mostly melted, gradually stir in remaining Pecorino in 2 to 3 batches, adding more pasta water as necessary to keep sauce silky. Once pasta is al dente, remove from heat and continue stirring gently until sauce is smooth.  Fold in cooked guanciale and serve with more Pecorino, if desired.