1.Place ingredients in a large saucepan or stockpot; simmer, uncovered, for 2 hours, skimming surface occasionally.
2.Strain stock through a fine sieve into a large heatproof bowl; discard solids. Allow stock to cool. Cover; refrigerate until cold. Skim and discard surface fat before using.
To cool rapidly cool stock place the saucepan in a sink of iced water, deep enough to reach halfway up the side of the pan. Stir frequently to release the heat. Refrigerate immediately. All stocks will keep in an airtight container in the fridge for up to 3 days or freeze for up to 3 months. Bring stock to the boil before using.