Preheat olive oil in a large skillet.
Pat dry chicken breasts with a paper towel. Season each side with salt and pepper, to you liking.
Place each breast into the skillet and cook over medium-high heat for 5 minutes on each side, or until all sides are no longer pink. (They will still be pink inside for now.)
Remove chicken breasts from the skillet and set aside on a plate.
To the skillet, still on medium-high heat, add heavy whipping cream, chicken broth, Parmesan cheese, minced garlic, and Italian seasoning. Use a wood spoon to stir together, and as you stir, use the wooden spoon to scrape up from the pan any brown bits left behind by the chicken.
Once the sauce has been well mixed, add the chicken breasts back to the skillet, and use a spoon to cover them with the sauce.
Place a lid over the skillet, reduce the heat to medium, and allow them to cook for 5-10 more minutes or until the center of the chicken breast reaches a temperature of 160F degrees.
Remove lid and remove skillet from heat.
Add in sun-dried tomatoes.
Add in fresh spinach leaves and carefully fold them into the sauce. They will wilt as they cook. Once they are wilted enough to be incorporated into the sauce, it is now ready to be served!