Place the chicken, onions, carrots, celery, garlic, bay leaves, thyme, parsley or dill, peppercorns, and salt in a large stockpot.
Add 12 cups of water and bring to a boil. If the water does not cover the contents of the pot, add a cup or two more water.
Reduce the heat to low and cook at a gentle simmer, uncovered, for about 4 hours. As it simmers, it is normal for some foam or scum to rise to the top. Use a spoon to remove it.
After three hours, taste and adjust the broth with more salt.
To strain the stock, use a slotted spoon to remove the larger pieces of bone and vegetables. Then, pour the stock through a fine-mesh strainer to catch all the smaller bits.
Transfer to containers and refrigerate for up to five days or freeze for up to 3 months.
After the stock has chilled, fat will rise to the surface. We usually leave this, but you can remove the fat for a leaner broth.
