01 - Season the chicken pieces evenly with salt, pepper, and Italian seasoning, ensuring all surfaces are coated.
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. Remove chicken from pan and set aside on a plate.
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 the 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 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 the pasta is al dente and most of the liquid has been absorbed.
07 - Return the cooked chicken to the pan. Add baby spinach and stir in Parmesan cheese. Cook for 2-3 minutes until the spinach wilts and the sauce thickens slightly. Taste and adjust seasoning if needed.
08 - Serve hot while the sauce is creamy and glossy. Garnish with chopped fresh parsley and additional Parmesan cheese if desired.