Place 3 pounds boneless skinless chicken breasts in the crock pot.
Add ½ cup butter, 2 tablespoons minced garlic, ½ teaspoon Italian seasoning, and ½ teaspoon salt over the chicken.
Cover and cook on Low for 5–7 hours or on High for 2½–3½ hours, until the chicken reaches an internal temperature of 165°F.
Remove the chicken from the crock pot and set aside.
In a small bowl, whisk together 2 cups heavy whipping cream, 1 tablespoon cornstarch, and 1 cup grated parmesan cheese until smooth.
Pour the cream mixture into the crock pot and whisk it into the cooking juices.
Stir in 2 cups chopped fresh spinach.
Return the chicken to the crock pot, placing it on top of the sauce.
Cover and cook on Low for 30 minutes, or until the sauce has thickened and the spinach is slightly wilted.
Serve warm as is or over pasta.
Notes
Helpful Tips
Cut Chicken - If your chicken breasts are very large, I suggest cutting them into smaller pieces.
Cooking Time - Cooking time will vary depending on your slow cooker and the size of your chicken. We recommend using a meat thermometer to ensure your chicken is fully cook with an internal temp of 165 degrees.
Variations Ideas
Change Chicken - You can easily substitute other cuts of chicken for chicken breasts. We like chicken thighs and chicken tenders for another great meal idea. If you use chicken thighs, keep in mind they take longer to cook.
Cream Cheese - For a richer taste to the sauce add cream cheese. You can add this to taste based on preference. Whisk as normal and pour into crock pot at the end to simmer. Cream cheese will make the sauce thicker so you may need to add more whipping cream.
Mushrooms - Add in 8 oz can of sliced mushrooms on top of the chicken in the slow cooker. This adds more delicious if you like mushrooms.
Make it Spicy - If you like dishes with a little heat, add a 1/2 teaspoon crushed red pepper flakes.
Add Vegetables - We love spinach in this but you can omit and try other things. Kale is good in this dish as well.