Step 1

Cut 1 boneless, skinless chicken breast into 1/2-inch thick strips and season all over with salt and pepper. Finely grate 3 ounces Parmesan cheese into a medium bowl (about 1 1/2 cups). Transfer 1/2 cup to a small bowl and reserve as garnish.

Step 2

Bring a large pot of salted water to a boil. Meanwhile, heat 1 tablespoon olive oil over medium heat in a large skillet until shimmering. Add the pancetta and cook, stirring occasionally, until just starting to brown, 1 to 2 minutes. Add the chicken and cook, stirring occasionally, until the chicken is cooked through and the pancetta is crisp, 4 to 5 minutes. Remove the pan from the heat.

Step 3

Add 12 ounces dried spaghetti to the boiling water and cook until al dente, about 10 minutes or according to package instructions. Meanwhile, place 4 large eggs and 1/2 teaspoon coarsely ground black pepper in the medium bowl of Parmesan and whisk well to combine. Coarsely chop a handful of parsley leaves for garnish if desired.

Step 4

When the pasta is ready, reserve 1/2 cup of the pasta water. Drain the pasta, then immediately add the pasta to the skillet off the heat. Pour the egg mixture over the pasta and use tongs or a fork to vigorously stir and toss to combine, adding 1 tablespoon of the reserved pasta water at a time as needed to evenly coat the pasta and chicken in a creamy sauce. (You’ll probably use only about 1 to 2 tablespoons of the pasta water.)

Step 5

Garnish with the parsley if using. Serve immediately with the reserved Parmesan and a few coarse grinds of black pepper.