Add the olive oil to a Dutch oven (or large, heavy-bottomed pot with lid, at least 4-qt capacity) over medium-high heat. Once the oil is hot and shimmering, add the carrots, celery, and onion. Season with 1 ½ teaspoons kosher salt, and stir to combine. Cook, stirring occasionally, until deeply browned and fragrant, 15-20 minutes. If the veggies begin to brown too quickly, reduce the heat to medium or medium-low. Once browned, push the soffritto mixture to the outer edges of the pot.

Add the Italian sausage to the center of the pot, such that it’s surrounded by the soffritto mixture. Reduce heat to medium. Let the sausage brown 2-3 minutes without touching it, then turn it over and brown the second side 2-3 minutes before using a wooden spoon to break it apart into bite-sized pieces. Stir to combine with the soffritto mixture.

Add the garlic and tomato paste to the Dutch oven, stirring to coat the Italian sausage soffritto mixture. Cook 2-3 minutes, until browned and fragrant. Deglaze the pot by slowly pouring in the white wine, using a wooden spoon to scrape up any browned bits that may have formed on the bottom of the pan. Let the wine simmer until it’s almost cooked off.

Tie the fresh herbs together using kitchen twine (or finely chop if you do not have twine), then add to the pot with the crushed tomatoes, fresh rosemary and thyme, bay leaves, parmesan rind (if using), and chicken stock or water (I start with about 1 cup of stock/water, then add more as needed as the sauce simmers). Stir to combine well.

Bring the sausage ragu sauce to a boil, then reduce heat to medium-low to maintain a very gentle simmer. Partially cover the pot (place the lid on the pot such that it’s just partially covered, allowing some steam to escape as the sauce simmers). Simmer the Italian sausage ragu sauce 90 minutes, stirring occasionally. If the sausage ragu sauce begins to reduce too much (losing too much of its liquid too quickly), feel free to add in a splash more broth/water and reduce the heat further. Once the sauce is simmered, remove and discard the spent herbs, bay leaves, and parmesan rind from the pot. Use At this point, you can cool and store for later use (see Recipe Notes for storage and freezing directions), or proceed with making the sausage ragu pasta (below).

About 20 minutes before the Italian sausage ragu sauce is ready, begin cooking the pasta. Bring a large pot of salted water to a boil. Once boiling, add the rigatoni and cook to al dente according to package directions, stirring occasionally to prevent sticking. Once cooked, carefully dip a liquid measuring cup into the pot to reserve about 1 cup of the starchy pasta water, and set aside. Carefully drain the pasta. (Learn more! ⇢ How to Cook Pasta Perfectly Every Single Time!)

Meanwhile, as the pasta boils, bring the slowly simmered Italian sausage ragu sauce up to a simmer. Stir in the heavy cream and parmesan cheese. Add the cooked rigatoni to the pot with the sausage ragu sauce, tossing to combine. The sausage ragu should evenly coat the pasta. Add in some of the reserved pasta water if the sauce needs to loosen up a little; add in an extra handful of parmesan if it needs to tighten up a little. Cook over medium heat for 1-2 minutes, allowing the pasta to meld with and absorb some of the sausage ragu.

Portion the Italian sausage ragu pasta into individual pasta bowls, topping with additional grated parmesan, chopped fresh herbs, and/or crushed red pepper as desired. Serve immediately. Enjoy!