Steps
1. Bring a pot of salted water to a boil and cook the spaghetti until al dente according to package instructions.
2. In a pan over medium heat, cook the diced guanciale until crispy, about 4-5 minutes. Remove from heat.
3. In a bowl, whisk together the egg, grated Pecorino Romano cheese, and a generous amount of black pepper until well combined.
4. Once the spaghetti is cooked, reserve a cup of pasta water and drain the rest.
5. Quickly add the hot spaghetti to the pan with guanciale, tossing to combine.
6. Remove the pan from the heat and pour the egg mixture over the pasta, tossing vigorously to create a creamy sauce. If necessary, add reserved pasta water to reach desired consistency.
7. Serve immediately, garnished with extra cheese and more black pepper if desired.