Rinse the chicken breasts under cold water and pat dry. Season both sides with salt and pepper. Heat olive oil in a skillet over medium heat and sear the chicken for 2-3 minutes on each side until golden brown.
In a small bowl, mix the ranch seasoning, brown gravy mix, garlic powder, onion powder, salt, and pepper until well blended.
Transfer the seared chicken to the slow cooker. Pour chicken broth over the chicken and sprinkle the seasoning mixture on top.
Cover the slow cooker and cook on low for 6-7 hours or on high for 3-4 hours.
Notes
Check the doneness of the chicken before serving; it should reach an internal temperature of 165°F.