2 heaping cups leeks, cut into 1-inch pieces (white and some light green parts only)
1½ cups Spanish onions, cut into 1-inch pieces
1 bay leaf
Instructions
Rinse the bones, necks, backs, and optional chicken feet thoroughly under cold water to remove all the visible blood. Remove any organs that may still be attached to the bones. (The rinsing of bones and removal of any organs is an essential first step in the clarification of the stock, as blood proteins are removed that would coagulate when heated and there will therefore be less chance that impurities will cloud your stock.)
Place all the bones and the feet, if using, in a 14- to 16-quart stockpot. Cover with the cold water. Slowly bring the liquid to a simmer, beginning to skim as soon as any impurities rise to the top. (It is important to keep skimming, because as the stock comes to a simmer, impurities could otherwise be pulled back into the liquid and emulsify and cloud the finished stock.
Once the liquid is at a simmer, add the ice and then remove the fat. (The ice will chill and thicken the fat and turn it opaque, making it easier to remove.) Skim off as much of the impurities as possible. (Once the vegetables are added, skimming will be more difficult.)
Add the aromatics and slowly bring the liquid back to a simmer, skimming frequently. Simmer for another 30 to 40 mins, skimming often. Turn off the heat and allow the stock to rest for 10 mins; this allows any particles left in the stock to settle at the bottom of the pot.
Set a chinois or fine-mesh strainer over a container large enough to hold at least 6 quarts. Use a ladle to remove the stock from the pot and strain it into the container. (It is important to ladle the stock rather than pouring it, as the force of pouring it out all at once would force impurities through the strainer.) Discard any stock toward the bottom of the pot that is cloudy with impurities.
Fill a sink with ice water and place the container in it to cook the stock rapidly. Stir occasionally until there are no traces of steam. Refrigerate for up to 3 days, or freeze in smaller containers for up to 2 months.
Recipe by Bistro OneSix at https://bistroonesix.com/ad-hoc-at-home-or-the-most-complex-soup-ive-ever-made/