For more depth of flavour in my stock, I roast the bones first. This gives me a richer, sweeter, darker stock that is great for sauces, soups and pasta dishes. No worries if you don’t have a pot big enough to hold the chicken bones and the 18 cups of water, just make half the recipe.
Preheat oven to 425 degrees F.
To make a roasted chicken stock: Add 1 tbsp. vegetable oil to large roasting pan. Add bones and roast in lower rack of oven until golden brown, about 15 to 25 minutes. Stir often to ensure even browning. Browning the bones will give a rich flavoured and dark coloured stock. Skip the browning step if you want a chicken stock with a mellow subtle flavour.
Transfer bones to an 8-quart stockpot. Add the onions, carrots, celery, leek, thyme, rosemary, peppercorns, cloves and bay leaves. Add enough cold water to cover and bring to a boil over high heat. As the water comes to a boil, skim off the scum that floats on top.
When the water comes to a boil, reduce heat to low and simmer stock very gently, uncovered, for at least 2 hours or up to 5 hours if you want a more concentrated flavour.
The liquid should barely bubble; if the stock boils it will be cloudy. And don’t stir it or push down on the bones – that will make it cloudy too.
Strain the stock through a fine sieve and cool. Transfer to shallow containers so the stock cools quicker. When cooled to room temperature, seal with plastic wrap or in airtight containers. Store in the refrigerator for up to 2 days or freeze until ready to use. Skim off the fat from the top of the stock before using. Makes about 16 cups, but yield depends on how long you simmer the stock.