2 lbs fish heads, tails, bones and trimmings
1 onion, halved
1 cup mushroom pieces
parsley
thyme
1 bay leaf
1 tablespoon lemon juice
4 cups water
1 cup white vinegar
Fish trimmings can be saved in the freezer until you have enough for a batch of stock. Avoid strong tasting, oily fish.
Bring ingredients to a boil.
Reduce heat, skim foam off surface and simmer for 30 minutes.
Strain carefully before using or freezing.
Makes approximately 4 cups stock.