Preheat the oven to 325°F. Arrange the roast in the bottom of a large, oven-safe Dutch oven. Season generously with salt and black pepper.
Roll the sausage into tiny meatballs and arrange them around the roast.
Add the onions, garlic, carrots, celery, Italian seasoning, bay leaves, and thyme. Pour over the crushed tomatoes, add the tomato paste, red wine, 2 cups water, and the star anise (if using). If you have a parmesan rind, add that too! Cover and roast for 3 1/2 to 5 hours or until very tender.
Shred the meat directly in the sauce until it is falling apart. Discard the star anise and bay leaves.
When ready to serve, cook the rigatoni pasta according to package directions until al dente. Drain the pasta and add it back to the pot with the sauce. Spoon over the Sunday sauce.
Add the heavy cream, grated Parmesan cheese, and unsalted butter. Toss to combine until the pasta is well coated.
Serve immediately with extra grated Parmesan and crispy butter-fried herbs (such as parsley or basil) for garnish. Enjoy your hearty meal!
For best flavor, let the sauce rest for 10-15 minutes before serving.