Preheat oven to 400 F. Place bones in a single layer on a sheet or roasting pan. Drizzle with olive oil to evenly coat.

Roast for 30 minutes, then, flip each bone over and roast for an additional 30 minutes.

Place roasted bones, chopped vegetables, bay leaf and cider vinegar in a large crock pot or soup pot and completely cover with water. Bring to a high simmer, then reduce heat to low.

Let simmer for 12-24 hours. Add water as needed to keep all the ingredients submerged.

Once the broth has reached a dark rich brown color, remove from heat. Discard the bones, vegetables and bay leaf and strain through a cheesecloth or wire strainer. Cool the pot to room temperature then pour into jars and cool in the refrigerator for at least 1 hour.

To serve, skim the condensed fat off the top of the broth and heat to the desired temperature.