Preheat oven to 400 F. Place bones in a single layer on a roasting pan and drizzle with olive oi. Roast for 30 minutes, then, flip each bone over and roast for an additional 30 minutes.

Put chopped vegetables, roasted bones, bay leaf and cider vinegar into a large stock pot or crock pot. Cover completely with water and bring to a high simmer. Reduce the heat to low and let simmer for 12-24 hours. Throughout simmering, 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. Cool the pot to room temperature. Pour into jars and let cool in the refrigerator for at least 1 hour.

When you are ready to serve, skim the condensed fat off the top of the broth and heat to the desired temperature.