Place the chicken breasts in the bottom of the slow cooker.
Pour in the chicken broth and add the minced garlic, Italian seasoning, chopped sun-dried tomatoes, salt, and pepper.
Cover and cook on low for 6 hours until the chicken is tender.
Remove the chicken, shred it with two forks, and return it to the slow cooker.
Stir in the heavy cream and fresh spinach. Cover and cook for 20 more minutes until the spinach wilts.
Turn off the heat and stir in the grated Parmesan cheese until it melts into the soup.