- 2 tablespoons [30 mL] vegetable oil
- 2 pounds [900 g] fresh fish heads, skin, bones and flesh
- 1 medium onion, thinly sliced
- 2 unpeeled medium carrots, into 2-inch [5-cm] long each pieces
- 6 fresh parsley sprigs
- 2 celery stalks with leaves, into 2-inch [5-cm] long each pieces
- 1 bay leaf
- 10 white peppercorns
- 5 fresh dill sprigs
- 1 cleaned unpeeled lemon, into thin slices
- Preheat vegetable oil into a 24-cup [6-L] casserole.
- Add and stir together fish heads, skin, bones and flesh over low heat for 2 to 3 minutes, without browning.
- Mix in onion slices, carrot pieces, parsley sprigs, celery pieces, bay leaf, white peppercorns, dill sprigs and thin lemon slices.
- Pour in enough water to almost cover all the ingredients.
- Bring to a boil over medium heat.
- Lower heat and leave to simmer slowly, uncovered, for 45 minutes.
- Pour fish stock, through a sieve lined with cotton cheese, into a bowl; leave to cool.
- Refrigerate stock for at least 2 hours.
- Using a slotted spoon, remove and throw away all the fat on top of broth.
- Use immediately, refrigerate or freeze fish broth.