Begin by patting the turkey breast dry with paper towels to achieve a nice sear and flavor.
In a small bowl, mix together the olive oil, garlic powder, onion powder, thyme, rosemary, sage, salt, and pepper to create a seasoning paste.
Rub the seasoning mixture all over the turkey breast, ensuring it is evenly coated.
Pour the chicken broth into the slow cooker.
Place the seasoned turkey breast into the slow cooker, ensuring it is submerged in the broth for extra moisture.
Cover the slow cooker with its lid and set it to low heat. Cook for 6 hours, or until the internal temperature reaches 165°F (75°C), checking with a meat thermometer.
Once cooked, carefully remove the turkey breast from the slow cooker and let it rest for about 10 minutes before slicing.
Optional: Use the remaining broth in the slow cooker as a gravy by thickening it with cornstarch or serving it as is.