Roast the winglets or carcasses in a moderately hot oven – 400°F (200°C) Gas 6 – until golden brown, about 20 minutes.
Roughly chop the vegetables and then pan-fry in the oil until lightly coloured.
Lift the winglets and vegetables into a large saucepan. Discard any grease or residual oil from the pans and deglaze them by boiling 1pint (600ml) water in first the frying pan then the roasting tray. Pour this liquor on to the bones.
Add a further 3pints (1.65litres) water and the peppercorns, bring to the boil and skim. Let the stock simmer for 1 hour, and skim periodically, topping up with fresh water as necessary, so that you end up with 4pints (2.25litres) of stock.
Combine the clarification ingredients in a food processor. The clarification mixture works better if it is well chilled. Many cooks mix ice cubes into it at this stage.
Skim any fat from the 4pints (2.25litres) stock and add the stock to the other ingredients in a large pot.
Bring to the boil. You should stir the stock regularly as it comes to the boil, as it has a tendency to stick to the pot base and burn. When the stock arrives at boiling point all the clarifying ingredients will form a white crust, underneath which you should have a crystal clear consommé.
Allow the consommé to simmer very gently for 1 hour, then strain it through wet muslin.
Reduce the consommé by gentle boiling until you have 2pints (1.2litres).