Combine the poultry wings, backs and necks and the onions in a stockpot. Cook over moderate heat
until the poultry and onion pieces are lightly browned, stirring from time to time so they colour
Add the water and stir well to mix in the sediment on the bottom of the pot. Bring to the boil
and skim off the impurities as they rise to the surface of the stock.
Add the remaining ingredients. Partially cover the stockpot and gently simmer the stock for
about 3 hours.
Strain the poultry stock into a bowl and leave to cool, then refrigerate.
When cold, carefully remove the layer of fat that will have set on the surface.