1. Place bones in a pot or a slow cooker. Add apple cider vinegar and water (enough to cover the bones), and let the mixture simmer for thirty minutes. This allows the vinegar to bind with minerals from the bones. 
2. Add vegetables and bring the broth to a boil. Remove the impurities that float to the surface. A foam layer can be easily scooped off with a big spoon and discarded. I typically check-in every twenty minutes or so for two hours to scoop foam from the top. 
3. After boiling for 2hrs, reduce heat to a low simmer, cover, and cook for an additional 24 hours (see below). Here's where a slow cooker comes in handy so you can safely leave it overnight. If your slow cooker is not large enough to accommodate this amount, you may start with a stockpot and once it boils down, switch to your smaller slow cooker. Alternately, you may half the recipe. 
4. During the last 30 minutes of cooking, throw in some garlic, and/or parsley for added flavour and minerals. 
5. Remove from heat and let the broth cool. Strain using a fine-meshed sieve or through a coffee filter to remove all the bits of bone from the broth. Add sea salt to taste. 
6. Drink the broth as is or store in the fridge in glass jars for up to 5–7 days or in the freezer up to 6 months for use in soups or stews. 

Note: after cooking, the broth will cool and a layer of fat will harden on top. This layer protects the broth beneath. Remove this layer only when you are about to use the broth. You can use this healthy fat for cooking instead of using seed oils.