MAKES 2 LITERS/3 1/2 PINTS

• 20g/Y40z unsalted butter


• 1 large onion finely chopped


• 1 leek. white part only, sliced


• 2 slices fennel


• 1.5kg/31b 5oz white fish bones and trimmings


• 350ml/12fl oz white wine

1. 
   Heat the butter in a stock pot and add the
   vegetables. Stir well then cover with a circle
   of dampened greaseproof paper and the lid.
   Cook very gently for about 20 minutes
   Stir frequently.
   
2. 
   Rinse the fish bones and trimmings under the cold tap
   and drain thoroughly. Chop the bones and any large
   heads into pieces.
   
3. 
   Add the fish to the pan and stir
   over a low heat for 3-4 minutes.
   
4. 
   Add the wine and leave to simmer for
   5 minutes, then add 2 litres/3 1/2 pints of cold
   water to the pot and bring it to the boil.
   Simmer the stock gently, uncovered,
   for 20 minutes, skimming from time to time.
   
5. 
   Strain the stock through a fine-meshed
   conical sieve. It can then be reduced and
   used immediately, or cooled and refrigerated
   for up to 24 hours. It can also be frozen.