In a large skillet, heat the olive oil over medium-high heat. If desired, sear the chicken breasts for 2-3 minutes on each side until lightly browned.
Place the chicken breasts in the crockpot.
In a mixing bowl, whisk together the ranch dressing mix, brown gravy mix, cream of chicken soup, chicken broth, garlic powder, onion powder, and black pepper until smooth.
Pour the mixture over the chicken in the crockpot, making sure it's evenly coated.
Cover the crockpot and cook on LOW for 6 hours or on HIGH for 3-4 hours, until the chicken is fully cooked and shreds easily with a fork.
Once cooked, shred the chicken using two forks and stir it into the gravy until well combined.
Serve the chicken and gravy over cooked rice or mashed potatoes.