01 - Season the chicken pieces thoroughly with salt, pepper, and Italian seasoning, ensuring even coverage on all sides.
02 - Heat olive oil and butter in a large, deep skillet over medium-high heat. Add seasoned chicken and cook until lightly browned and cooked through, about 5-6 minutes. Remove chicken and set aside.
03 - In the same pan, add chopped onion and sauté for 2-3 minutes until softened and translucent. Add minced garlic and cook for 30 seconds until fragrant, being careful not to burn.
04 - Stir in diced red bell pepper and cook for another 2 minutes until slightly softened but still retaining some crunch.
05 - Add uncooked pasta to the pan, followed by chicken broth and heavy cream. Stir well to combine, making sure to scrape up any browned bits from the bottom of the pan for added flavor.
06 - Bring the mixture to a gentle simmer. Cover with a lid and cook for 10-12 minutes, stirring occasionally to prevent sticking, until pasta is al dente and most of the liquid has been absorbed.
07 - Return cooked chicken to the pan along with baby spinach and Parmesan cheese. Cook for 2-3 minutes, stirring until spinach wilts and sauce thickens slightly.
08 - Taste the dish and adjust seasoning with additional salt and pepper if needed. Serve hot, garnished generously with chopped fresh parsley and extra Parmesan cheese if desired.