Place duck legs in base of large slow cooker.

Add fat, garlic, shallot, salt, pepper and herbs.

Cover and set slow cooker to HIGH and cook for 1 hour.

Reduce heat to LOW and cook until duck is very, very tender - at least 4 and up to 8 hours.

Use slotted spoon to remove duck from fat which can be strained, frozen and reused.

To reheat duck to serve, place under a hot grill for 10 minutes turning half way through cooking time.