In bowl, combine peanut sauce, coconut milk and brown sugar.
Cut chicken into thirds; sprinkle with salt and pepper.
In zip-top freezer bag, layer next 4 ingredients, chicken and sauce mixture.
Seal and freeze flat.
Thaw freezer bag in fridge overnight before desired cooking date.
Transfer contents to slow cooker.
Cover; cook on low until chicken is tender, about 8 hrs.