01 - Season chicken pieces thoroughly with salt, black pepper, and Italian seasoning, ensuring even coating on all sides.
02 - Heat olive oil and butter in a large deep skillet over medium-high heat. Add seasoned chicken and cook for 5-6 minutes until lightly browned and cooked through. Transfer chicken to a plate 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 continue cooking 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 mixture to a gentle simmer, then cover and cook for 10-12 minutes. Stir occasionally to prevent sticking and ensure even cooking. Pasta should be al dente and most liquid absorbed.
07 - Return cooked chicken to the pan along with baby spinach and Parmesan cheese. Cook for 2-3 minutes, stirring constantly, 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.