Fill a large pot with water, adding a generous amount of salt, and bring it to a rolling boil. Cook the rigatoni according to the package instructions until al dente. Before draining, reserve 1/2 cup of the pasta cooking water. Once cooked, drain the remainder and set the rigatoni aside.
In a large skillet, heat olive oil over medium heat. Remove the casing from the Italian sausage, crumbling the meat directly into the skillet. Cook, stirring frequently, until the sausage is nicely browned and cooked through, which should take about 5-7 minutes.
Add the finely chopped onion to the skillet with the sausage. Sauté for about 3-4 minutes, or until the onion becomes translucent. Then, add the minced garlic and continue to cook for an additional minute, allowing the garlic to become fragrant without burning.
Pour the chicken broth into the skillet, bringing it to a gentle simmer. Lower the heat and stir in the heavy cream, mixing thoroughly to combine. Allow the sauce to simmer for about 2-3 minutes, or until it thickens slightly.
Gently fold the cooked rigatoni into the sauce, followed by the grated Parmesan cheese. If the sauce appears too thick, gradually add the reserved pasta water, a little at a time, until you reach your desired consistency. Finally, season the dish with the dried Italian herbs, along with salt and pepper to taste.
Remove the skillet from the heat and transfer the creamy rigatoni to serving plates. Garnish with freshly chopped parsley and serve immediately.
Notes
Serve in deep bowls with extra Parmesan and a drizzle of olive oil for added richness.