01 -
Spray your slow cooker with nonstick cooking spray.
02 -
Place the diced onion on the bottom of the slow cooker. Layer the boneless chicken breasts on top of the onion.
03 -
Evenly sprinkle the ranch seasoning mix and au jus gravy mix over the chicken. Scatter the whole pepperoncini peppers around and pour in the pepperoncini juice.
04 -
Arrange the slices of unsalted butter over the chicken.
05 -
Cover and cook on low for 6-8 hours, or on high for 4-5 hours, until the chicken is tender and fully cooked.
06 -
Use forks to shred the cooked chicken in the pot, mixing well with the juices.