Place chicken breasts in the slow cooker.
Sprinkle ranch dressing mix evenly over the chicken.
Add pepperoncini peppers and their juice on top.
Slice the stick of butter and place it over the chicken.
Pour chicken broth into the slow cooker.
Season with salt and pepper.
Cover and cook on low for about 6 hours.
Shred the chicken with two forks in the sauce.
Serve hot, garnished with fresh parsley.