Fish Stock

• 2 kg white fish bones, sole, turbot, brill, etc.
• 2 medium leeks,

Wash the bones in cold water. Put them into a pot with the rest of the ingredients, cover with cold water and bring it to the boil. Skim off any scum that forms and simmer for 20 minutes, skimming occasionally. Strain through a fine-meshed sieve. Check its strength and reduce if necessary.