Steps

Bring a pot of salted water to a boil. Add the pasta and cook until al dente, according to package instructions. Reserve some pasta cooking water before draining.

In a pan over medium-low heat, cook the guanciale until the fat has rendered and it becomes crispy and golden. Remove the guanciale and set aside so it doesn't get soggy as we make the sauce.

In the same pan but on medium heat, add the sausage and break it up with a spoon as it cooks until browned.

Add the crushed San Marzano tomatoes to the skillet with the sausage. Let them simmer for about 10-15 minutes, allowing the flavors to meld and the sauce to thicken slightly. Return the crispy guanciale to the skillet and mix well.

In a small bowl, whisk the egg yolk with the grated Pecorino Romano. Add a small amount of reserved pasta water to help create a smooth mixture.

take the sauce off the heat and add the cooked pasta, tossing to coat the pasta well. Stir in the egg and cheese mixture, ensuring the pasta is well coated. Add more reserved pasta water as needed to achieve a creamy consistency. Season with salt and freshly ground black pepper to taste.

Serve immediately, garnished with additional Pecorino Romano and freshly ground black pepper if desired.