• Bring a large pot of water to a boil and add a pinch of salt.
• Start cooking the remaining ingredients before adding the rigatoni pasta.

Make the Egg Yolk Mixture

• In a heatproof bowl mix the egg yolks, Parmesan cheese and black pepper together well.

Brown the Guanciale

• To a large Dutch oven or 5-quart pot over medium heat, add the guanciale and olive oil. Cook until brown and crispy, 5 to 8 minutes.
• Remove with a slotted spoon and set aside.
• Remove 1 Tablespoon of fat from the pan and add it to the egg yolk mixture. Whisk well to combine.

Cook the Aromatics

• Add the onion and garlic to the pot and sauté, stirring occasionally to cook the onions until softened, 2 to 3 minutes.

Add More Ingredients

• Add the Italian sausage and cook for 8 to 10 minutes, stirring occasionally to crumble the sausage, until cooked through.
• Stir in the tomato paste and cook for about 2 minutes.
• Add the tomato purée and red pepper flakes and mix well.

Simmer the Sauce

• Reduce the heat to a simmer, cook for about 10 minutes.

Cook the Pasta

• Meanwhile, cook the pasta according to package instructions, about 10 minutes.
• Reserve at least 1 cup of the pasta water, drain the pasta and set it aside.

Combine Pasta and Sauce

• Turn off the heat to the sauce and stir in the pasta and about ¾ of the cooked guanciale and stir to coat.
• Add a ladle (about ½ cup) of pasta water to the pot, then add the egg yolk mixture, mixing continually to combine thoroughly.

Thin the Sauce

• If the sauce is too thick, add more of the pasta water, a couple tablespoons at a time, and stir to incorporate well.

Garnish and Serve

• Serve immediately, topped with remaining guanciale and extra cheese.