Place the chicken on the bottom of the slow cooker, and season the tops with salt and pepper, to taste.
In a medium mixing bowl, stir together the chicken broth, tomato paste, Italian seasoning, and red pepper flakes, then pour over the chicken in the slow cooker.
Next, add the pepperoni and the olives to the slow cooker.
Cover and cook for 3 hours on high or 6 hours on low. , or until the chicken falls apart and can be easily shredded.
Shred the chicken in the slow cooker with tongs or 2 forks, and mix it up to absorb the remaining liquid for an additional 30 minutes.