To make the stock: Roughly cut up the carrots, celery and onion. Add them to a large pot with with the pork ribs (if using) and pour over 1.5 litres of cold water. Add the parsley, bay leaf and allspice berries. Simmer the stock on a very gentle heat (barely boiling) for an hour. Skim any foam that forms with a large spoon and discard. Strain the stock. You can use the pork ribs
to make these roasted ribs.