- 4 ounces guanciale, cut into 1/4-inch cubes
 - 1 tablespoon olive oil
 - 1 teaspoon ground black pepper, or to taste
 - 2 eggs
 - 3 tablespoons grated Parmigiano-Reggiano cheese
 - 3 tablespoons grated Pecorino Romano cheese
 - 1 teaspoon ground black pepper, or to taste
 - 6 ounces spaghetti
 - 1 cup reserved pasta water
 - 3 tablespoons grated Parmigiano-Reggiano cheese
 - 3 tablespoons grated Pecorino Romano cheese
 
- Cook guanciale with olive oil and 1 teaspoon ground black pepper in a Dutch oven over medium-low heat until almost crisp, about 5 minutes. Reduce heat to low.
 - Whisk eggs, 3 tablespoons Parmigiano-Reggiano cheese, 3 tablespoons Pecorino Romano cheese, and 1 teaspoon ground black pepper in a bowl. Set aside.
 - Bring a large pot of lightly salted water to a boil. Cook spaghetti in the boiling water, stirring occasionally until cooked through but firm to the bite, 10 to 12 minutes. Drain, reserving 1 cup of the pasta water.
 - Pour reserved pasta water and drained spaghetti into the bacon-pepper mixture; stir to combine.
 - Slowly pour egg mixture into the pasta mixture; cook, stirring constantly until the egg mixture forms a thick sauce, 1 to 2 minutes. Remove from heat.
 - Stir remaining 3 tablespoons Parmigiano-Reggiano cheese and 3 tablespoons Pecorino Romano cheese into the pasta mixture and serve.