Pat chicken breasts completely dry with paper towels. Season both sides with salt, pepper, and Italian seasoning.
Heat olive oil in a large skillet over medium-high heat until shimmering. Add chicken and sear undisturbed for 5-6 minutes per side until golden brown and cooked through (165°F internal). Remove to a plate and tent with foil. Let rest at least 5 minutes before slicing.
Meanwhile, bring a large pot of salted water to a boil. Cook rigatoni according to package directions. Reserve ½ cup pasta water before draining.
In the same skillet over medium heat, add minced garlic and sun-dried tomatoes. Sauté for 2 minutes until garlic is fragrant and just golden. Add red pepper flakes and Italian seasoning, stir 30 seconds.
Pour in chicken broth and scrape up all browned bits from the bottom of the pan. Simmer 2 minutes until slightly reduced.
Add heavy cream and stir to combine. Bring to a gentle simmer and cook 5 minutes, stirring occasionally, until sauce thickens slightly to a blush color.
Remove skillet from heat. Stir in freshly grated parmesan until fully melted and smooth. Taste and adjust salt.
Add drained rigatoni to the sauce and toss to coat, adding pasta water as needed to loosen the sauce.
Slice rested chicken and fan over the pasta. Garnish with fresh basil and extra parmesan. Serve immediately.