Fond de volaille

Name: Fond de volaille
Yield: Makes about 1.25 litres (2 pints/1¼ quarts)
Cuisine: French
Ingredients: 150 g (5½ oz/⅔ cup) onion, roughly chopped; 1 kg (2¼ lb) chicken bones; 1 celery stick; 4 garlic cloves; coarse salt and pepper; 1 bouquet garni; 150 g (5½ oz/⅔ cup) trimmed leeks, roughly chopped; 150 g (5½ oz/⅔ cup) carrots, roughly chopped