In a small saucepan, melt butter. Add minced garlic, and cook until fragrant, about 1 minute.
Add chicken stock and heavy cream. Simmer on low for 5-7 minutes. Add in parmesan cheese and stir to combine. Turn off heat.
Place chicken thighs at the bottom of a slow cooker.
Sprinkle Italian seasoning and salt over top of chicken thighs. Add in sun dried tomatoes and pour cream sauce over top to cover.
Place lid on slow cooker and cook on high for 3-4 hours, or on low for 5-6 hours.
After the cooking time is complete, take chicken breasts out and set to the side. Add in spinach, and stir until it wilts.
Add chicken back to slow cooker, and you are ready to serve. This would be great on pasta, or with a side of broccoli or cauliflower. I also like to serve with an extra grate of fresh parm over the top!