In a medium mixing bowl, whisk together the Greek yogurt, olive oil, oregano, garlic powder, thyme, salt, pepper and thyme.
Add the chicken breasts to a gallon sized zippered food storage bag.
Pour the yogurt mixture over the chicken in the bag.
Seal the bag and massage the chicken and yogurt through the bag to coat all the chicken in the marinade.
Place bag in the refrigerator and let the chicken marinate for at least 4 hours but preferably overnight.
Empty the contents of the bag into a 5 to 6 quart slow cooker.
Cover and cook on LOW for 4 to 6 hours or until chicken is cooked through.
Freezer Meal Instructions:
Place all ingredients into a 1 gallon size zippered freezer bag OR FoodSaver bag.
Place bag on flat surface and seal bag closed while pressing out as much excess air as possible OR use your FoodSaver sealing system to vacuum seal the bag closed.
Label bag with date prepared, name of recipe, ingredients and cooking instructions.
Lay bag flat in freezer and allow to freeze for several hours. At that point you can stand the bags upright in your freezer if desired.
To Cook Freezer Meal:
Remove freezer meal bag from freezer and place either in refrigerator overnight OR in a clean kitchen sink filled with cool water for several hours just until the freezer meal is partially thawed enough to dump the contents of the bag into the slow cooker.
Cook according to the recipe directions adding 1 additional hour cooking time (in this case 5 to 7 hours on LOW from the partially thawed state ).