Place the chicken breasts in the bottom of your crockpot.
Sprinkle the ranch seasoning mix and au jus gravy mix evenly over the chicken.
Add black pepper and optional garlic/onion powder for extra flavor.
Place butter on top of the chicken.
Arrange pepperoncini peppers around and on top of the chicken.
Cover and cook on low for 6–7 hours or high for 3–4 hours, until chicken is tender and easily shredded.
Remove the chicken and shred with two forks. Return shredded chicken to the crockpot and stir to combine with the juices.
Serve hot over rice, mashed potatoes, noodles, or as a sandwich filling.