Rinse the chicken under cold water and trim away any excess fat.
Place chicken and all remaining ingredients in a 10-litre stockpot and bring to the boil. Reduce the heat to a gentle simmer, skimming with a ladle to remove any impurities. Turn down the heat until the surface of the stock is barely moving and cook for 2 hours, skimming as required.
Remove stock from the heat, strain the stock through muslin and store in refrigerator for up to 3 days or in freezer for 2–3 months.