Place all the ingredients in your slow cooker. Cook on low heat for 7-8 hours or high heat 3-4 hours until chicken is cooked through.
After chicken has cooked, use two forks and shred chicken. It should be very easy to shred, if it isn't cook further until it is. Cover the slow cooker again and let shredded chicken cook another 20 minutes or so to mingle with and thicken the sauce. After this point, if sauce is too thick, you can add a little more chicken stock.