Pasta alla Gricia

Heat oil in a large skillet over mediumlow. Cook guanciale, stirring often, until it starts to brown and crisp, 10 –15 minutes; it will shrink dramatically as the fat renders. Transfer to a small bowl with a slotted spoon; reserve skillet (do not wipe out). Meanwhile, cook pasta in a large pot of boiling lightly salted water, stirring occasionally, until pasta is about halfway cooked (not quite al dente); drain, reserving 1 1/2 cups pasta cooking liquid. Add 3/4 cup pasta cooking liquid to reserved skillet and bring to a gentle boil over medium heat, swirling often to encourage drippings and liquid to emulsify, about 1 minute. Add pasta and cook, tossing often and adding more pasta cooking liquid as needed, until pasta is al dente and a thick, glossy sauce forms, 5 –7 minutes (this second cooking is why you undercook the pasta initially). Increase heat to medium-high. Add guanciale, pepper, and two-thirds of Pecorino; toss well to combine and melt cheese. Serve pasta topped with remaining Pecorino.