1. Place a large pot of salted water over high heat and bring to a rapid boil. Add the vegetable oil and rigatoni to the water and cook according to the directions on the package, 10 to 12 minutes.
2. While you are waiting for the water to boil, pour the heavy cream into a large saucepan over medium heat. Add the chopped fresh rosemary and fresh garlic to the cream and bring it to a simmer – take care not to let it boil over. Allow the cream to reduce by about half.
3. Stir in the goat cheese and shredded roasted chicken and continue cooking it till the cream coats the back of a spoon.
4. Thoroughly drain the pasta. Add the pasta to the sauce. Coat the pasta in the sauce and simmer over low heat for a few minutes. Serve hot.
