4–5 stalks celery, very thinly sliced, leaves reserved
Freshly ground black pepper
Add the onion, cayenne pepper hot sauce, chicken stock, apple cider vinegar, butter, salt, garlic powder, and dried oregano to the bottom of your slow cooker and stir well to combine. Add in the chicken breasts and cook on high for 3 to 4 hours or until the chicken is cooked through and can be easily pulled apart.
Remove the chicken to a bowl and shred with two forks. Pour the sauce that remains in the slow cooker onto the chicken and stir to combine. If the sauce seems a little thin, pour it into a small saucepot and set it to simmer for 10 to 15 minutes just to reduce and thicken before mixing with pulled chicken.
In a bowl, stir together the mayonnaise, sour cream, blue cheese, vinegar, chives, and sliced celery and leaves. Season with salt and pepper to taste.
Divide the chicken between the rolls and top each sandwich with some of the celery blue cheese slaw and dig in!