Fish balls (cakes)

Here is a classic from Asia

Ingredients
Fish bones and trimmings
couple of sliced onions
handful of parsley and stalks
squeeze of lemon juice
a half dozen crushed black peppercorns
2 litres of cold water


Method
Put the ingredients into a pot and cover with water
Bring to boil and quickly allow to simmer gently for 20 minutes (any longer and
the stock can go bitter). Strain the liquid.
This stock can be thickened to make a delicious base for a fish mornay, using
the trimmings and the meat that falls or is picked off the backbone