Place chicken and veal knuckle in a large stock pot with 4 quarts of water and bring to a boil, skimming until scum no longer rises to the surface. Simmer for 1 hour. Add leeks, onion, carrots, celery, garlic, and parsley. Add salt and pepper to taste and continue to simmer for 1 hour. Correct seasoning and strain through a fine sieve. Cool, remove fat, and use or store in refrigerator.{$7e}(Original recipe for 4)