Place the boneless, skinless chicken breasts evenly in the bottom of your slow cooker.
Evenly sprinkle the au jus gravy mix and ranch dressing mix over the top of the chicken.
Add the stick of salted butter in pieces across the chicken and then arrange the peperoncini peppers on top.
Cover the slow cooker and let it cook on low heat for 6 to 8 hours until the chicken is tender and cooked through.
Once done, shred the chicken directly in the slow cooker using two forks and mix it well with the juices before serving.