2 T olive oil
4 ounces pancetta or bacon, cut into ¼-inch pieces
1 small shallot, finely chopped
2 garlic cloves, finely chopped
4 large egg yolks
1 large egg
3 ounces mixed salty hard cheeses - Parmesan, Pecorino, and/or Grana Padang
2 t freshly ground black pepper
12 ounces strozzapreti or other short pasta
8 small radishes, trimmed, cut into ½-inch pieces
2 T chervil leaves with tender stems
Heat oil in a large skillet over medium. Cook pancetta, stirring occasionally, until just beginning to crisp, about 5 minutes. Add shallot and garlic and cook, stirring often, until softened but not browned, about 1 minute. Transfer mixture to a large bowl and let cool slightly. Mix in egg yolks, egg, cheese, and pepper. Wipe out and reserve skillet.
Meanwhile, cook pasta in a large pot of boiling salted water, stirring occasionally, until al dente. Drain, reserving ½ cup pasta cooking liquid.
Add pasta, ¼ cup pasta cooking liquid, and radishes to sauce; toss to combine. Transfer to reserved skillet and cook over low heat, moving skillet on and off heat, to keep sauce from curdling, and stirring constantly, until sauce is smooth and coats a wooden spoon, about 2 minutes.
Divide pasta among bowls and top with chervil, if desired.