Heat olive oil in a pan over medium heat and sauté onions and garlic until translucent.
Add the sautéed mixture to the crock pot with the chicken, broth, and Italian seasoning.
Cover and cook on low for 6-8 hours or on high for 3-4 hours until chicken is fully cooked.
Remove the chicken from the crock pot, shred it, and return it to the pot.
Stir in the heavy cream and Parmesan cheese until melted and combined.
Add in the chopped spinach and stir until wilted.
Season with salt and pepper to taste before serving.