Add the cow heel to the slow cooker.
Roughly chop the carrots, onion, pimento peppers, garlic, turmeric root, chives and cilantro. Add to the slow cooker.
Add the water, bay leaves, sprig of oregano, apple cider vinegar, salt and black pepper.
Cover the slow cooker and allow the bones to simmer for at least 14 hours.
When cooking is finished, adjust for salt then carefully strain the broth through a mesh strainer to remove the solids.
Pour into a bowl or mug and enjoy immediately or allow it to cool fully before storing in the refrigerator for up to 4 days or up to 2 months in the freezer.
Note that when the broth is chilled, it becomes gelatinous due to the collagen. The fat sits at the top and can be easily removed, if you prefer.
Other than enjoying this broth on its own, it can be added to soups, sauces, stews and gravies.