Place the chicken breasts in the base of your slow cooker.
Sprinkle the ranch dressing mix and au jus gravy mix evenly over the chicken.
Add the salted butter on top, breaking it into smaller pieces if needed.
Layer the peperoncini peppers over everything.
Cover the slow cooker and cook on low heat for 6 to 8 hours, allowing the chicken to cook thoroughly and release its own juices.
Once cooked, shred the chicken directly in the slow cooker using two forks.
Serve hot and enjoy your easy and delicious Crock Pot Mississippi Chicken!