Place the chicken pieces into the slow cooker, add garlic, and season with salt and pepper.
Melt butter in the microwave
In a small bowl, add the soy sauce, honey, ketchup, butter, and apple cider vinegar. Stir to combine all of the ingredients.
Pour the sauce over the chicken.
Cover and cook on low for 5 hours or on high for 3 hours.
Remove the chicken from the slow cooker 5 hours after it started to cook.
Add the cornstarch to the sauce in the slow cooker and stir to combine.
Return the chicken to the slow cooker and continue cooking for 1 hour.
Serve with rice if desired.
Top with green onion.
Serve on top of white rice and a side of vegetables if desired