Bring a large pot of salted water to boil and cook spaghetti until al dente.

While pasta cooks, fry guanciale in a pan until crispy.

In a bowl, whisk eggs and Pecorino until creamy.

Reserve some pasta water, then drain spaghetti.

Turn off heat, toss spaghetti with guanciale, then quickly stir in egg mixture.

Add reserved water if needed to reach a creamy consistency.