If chicken feet still have yellow membranes on the outside, prepare a blanching station. Set an ice-bath next to a large pot of water. Bring water to a boil.

While the water heats, rub the chicken feet with salt.

Once boiling, use a slotted spoon to add the feet and submerge. Quickly remove and place in the ice-bath to prevent cooking.

Peel the yellow membrane from the outside and discard.

Add prepped chicken feet to a slow-cooker along with fish sauce, vinegar, leeks and carrot pieces. If fish sauce is unavailable, use 1 tablespoon of sea salt. 

Top with about 12 cups of water.

Turn slow-cooker to high. Once boiling, turn heat down to low and let the broth cook for at least 24 hours. 

Strain the chicken feet and vegetables and discard. Taste to adjust salt, if preferred.

Store broth in jarring cans in the refrigerator for a couple of days or freeze for a few months.