01 - Bring a large pot of salted water to a boil. Cook rigatoni according to package directions until al dente. Reserve 1/2 cup of pasta water, drain, and set pasta aside.
02 - Heat olive oil in a large skillet over medium-high heat. Add chicken, season with salt, pepper, and Italian seasoning, and cook for 5 to 7 minutes until golden brown. Remove chicken from skillet and set aside.
03 - In the same skillet, melt butter over medium heat. Add minced garlic and sauté for 30 seconds until fragrant. Pour in chicken broth and simmer for 2 minutes, scraping up any browned bits from the bottom.
04 - Stir heavy cream into the skillet and simmer for 3 to 4 minutes until slightly thickened. Add Parmesan cheese and mix until the sauce is smooth. If necessary, thin the sauce with reserved pasta water until desired consistency is reached.
05 - Return cooked chicken to the skillet, tossing it in the sauce. Add rigatoni and gently mix until all ingredients are fully coated. Allow to simmer together for 1 to 2 minutes.
06 - Remove from heat. Garnish with fresh parsley, additional Parmesan, and red pepper flakes if desired. Serve immediately while warm.