Spray the bottom of slow cooker with cooking spray, add the chicken and season with salt and pepper. Add half a cup of chicken broth or water. Cook on low for 5-6 hours, or high for about 2.5-3 hours. Shred chicken right there in the slow cooker using two forks, or remove to stand mixer if you want to shred that way. (You can put all the ingredients besides toppings in if you want to skip the extra step and cooking time at the end, the beans just don't hold up as well as I like, but it's still delicious! You can remove the chicken and shred then return to the pot to mix before serving.)