Place the chicken breasts in the slow cooker. Sprinkle them with salt, pepper, and Italian seasoning.
Add the minced garlic, sun-dried tomatoes, and chicken broth around the chicken.
Cover and cook on low for 5 to 6 hours until the chicken reaches an internal temperature of 165°F.
Remove the chicken to a plate and stir the heavy cream and Parmesan into the sauce left in the slow cooker.
Add the fresh spinach and stir until it wilts, about 5 minutes.
Return the chicken to the slow cooker and spoon the sauce over the top before serving.