1 kg fish bones and trimmings
500g whitefish, such as cod
1 medium onion, thinly sliced crossways
1 leek, thinly sliced
1 carrot, thinly sliced
2 tablespoons lemon juice
bouquet garni (10 fresh parsley sprigs, 1 fresh thyme sprig and 1 bay leaf)
2 litres water
12 black peppercorns
1/2 teaspoon salt
To make bouquet garni, tie together herb sprigs with a piece of string or place in a muslin bag; if string is used the bouquet garni can be tied to the pan handles for easy removal.
Place all ingredients in a large saucepan or casserole over moderate heat. Bring to the boil, lower temperature and simmer gently, uncovered, for 30 minutes.
Skim surface as required during cooking. Pour through a fine strainer, then cool. Cover tightly and store in the refrigerator for up to 2 days.
Makes about 1.2 litres.
For a rich stock use three-quarters water and one-quarter dry white wine. Strain liquid, then return to the cleaned pan and boil over high heat until reduced to two-thirds.