Heat the olive oil in a Dutch oven over medium heat. Add the fennel and onion and saute for 7 minutes, stirring occasionally, until tender. Add the sausage and cook for 7 to 8 minutes, crumbling it, until nicely browned. Add the garlic, crushed fennel seeds, red pepper flakes, 2 teaspoons salt, and 1 teaspoon black pepper and cook for one minute. Pour in the wine, bring to a boil, and add the heavy cream, half-and-half, and tomato paste. Bring back to a boil, lower the heat, and simmer for 20 minutes, until the sauce has thickened.

Meanwhile, bring a large pot of water to a boil, add a generous amount of salt, and cook the rigatoni according to the directions on the package.

Drain rigatoni and add to the sauce, stirring to coat the pasta. Cook over low heat for 5 minutes to allow the pasta to absorb the sauce. Off the heat, stir in the parsley and parmesan

Serve with more grated parmesan if desired