Wash, pat dry, then place chicken in a single layer in the slow cooker. Whisk together the rest of the ingredients in a bowl and pour over the chicken. Flip the chicken so that both sides are coated with the liquid sauce. Cook on low for 4 hours.
Shred the chicken inside the slow cooker in order for the meat to soak up the sauce. Remove from the sauce.
Spoon off any fat from the top of the sauce. When ready to use, transfer to a small pan and simmer over medium heat until it thickens a little bit, 10-15 minutes. If prepping in advance, transfer the sauce to a storage container and reheat when ready to enjoy. *
* It's important to store the sauce separately as it's needed only for meal #1. Meal #2 and #3 will use just the chicken.