1/2 pound (8 oz.) dry pasta – bucatini, spaghetti, or any long pasta
1 whole egg
2 egg yolks
1/3 cup grated Parmigiano Reggiano, plus more for serving
1/3 cup grated Pecorino Romano
Salt and freshly ground pepper, to taste
1 tablespoon olive oil
4 ounces pancetta, bacon or guanciale, diced (1/3 cup bacon)
Chopped parsley to garnish (optional)
Directions
Bring a large pot of salted water to a boil. Add pasta, and cook until almost al dente (about 2 minutes less than package instructions).
While the pasta is cooking, mix the egg, yolks, cheese, salt, and pepper in a medium bowl, and set aside.
Heat olive oil in a large skillet, over medium-high heat. Add diced pancetta and cook until crispy and golden brown, about 5 minutes. Remove the pan from heat and reserve pancetta with about 3 tablespoons of the rendered fat.
When the pasta is done, drain it in a colander set over a large mixing bowl, letting the hot pasta water heat the bowl. Reserve 1 cup of starchy water.
Discard the remaining water, and use the warmed bowl to toss the pasta with the egg mixture and pancetta, along with 1/4-1/2 cup pasta water. Work quickly, tossing vigorously and adding more pasta water if necessary, until the sauce is silky and the cheese has melted completely. Taste, and add more salt and pepper if needed.
Garnish with chopped parsley and serve with extra Parmigiano Reggiano at the table.