Bring a large pot of water to a boil, salt it and cook the pasta al dente according to the directions on the package. Reserve 1-2 cups of pasta water before draining.
Meanwhile, heat the olive oil in a large deep pan or Dutch oven and melt the butter in it. Add the cubed chicken breast and cook for 5-6 minutes until slightly golden.
Stir in the onion, garlic and red chili flakes and cook for 2 more minutes, occasionally stirring, until the onion is softened.
Add the Italian seasoning and tomato puree (passata) and stir to combine, then stir in the cream.
Allow the sauce to bubble for 2-3 minutes on low heat, then add the cooked pasta and stir in the grated parmesan.
Add the fresh parsley, season to taste and serve immediately