Bring a large pot of salted water to a boil. Cook 12 oz rigatoni just shy of al dente (about 1 minute less than the package says). Reserve 1 cup of pasta water, then drain.
Heat 1 tablespoon olive oil in a large sauté pan over medium heat. Add 4 oz guanciale and cook until just crisp, about 4 minutes. Add 1/2 lb Italian sausage, breaking it into chunks, and cook until browned, about 5 more minutes.
Stir in 1/2 chopped onion, sauté until translucent, about 3 minutes. Add 2 minced garlic cloves and 1/2 tsp red pepper flakes (if using), and cook for 30 seconds until fragrant.
Add 1 tablespoon tomato paste, stir it into the fat, then deglaze with 1/2 cup dry white wine. Simmer for 2–3 minutes. Add 1 cup crushed San Marzano tomatoes and cook down for 5–6 minutes until thickened slightly.
In a small bowl, whisk together 2 egg yolks, 1 whole egg, 1/2 cup Pecorino Romano, and a big pinch of black pepper. Set aside.
Add the drained rigatoni to the sauce with a splash of reserved pasta water. Stir to coat the pasta and let everything meld over low heat for a minute.
Remove the pan from heat. Slowly drizzle the egg-cheese mixture into the pasta, tossing constantly to prevent scrambling. Add a splash more pasta water to loosen if needed. Finish with lemon zest and extra Pecorino to taste.
Top with more Pecorino, black pepper, and fresh herbs if using. Serve immediately—with crusty bread to mop up any sauce, of course.