Set oven to 300 degrees F. Season the duck legs with salt and pepper on both sides and then sear in a tablespoon of duck fat until golden brown on both sides.
Remove from pan and set aside.
Add the onion, carrot, celery, and garlic and cook until tender.
Next add the the coriander, white peppercorn, star anise, and herbs (all tied in cheeseclothsachet).
Continue cooking for additional 5 minutes.
Add the duck fat, melt, and then transfer all to oven-proof casserole.
Cover with aluminum foil and cook for 6-8 hours, until duck meat falls off the bone.
When cool enough to handle, pull the duck meat off the bone, discard the bones and be careful of loose cartilage.