Adjust the seasoning to taste, sprinkle on the chopped parsley, and serve very hot, in warm bowls. Simmer for 10 to 15 minutes, until the rice is cooked (but not mushy) and the fish is tender and flakes apart in the broth. Stir in ½ cup rice for every quart of broth (or more rice for denser consistency) and the pieces of fish fillet, if using. Return the broth (or as much of it as you want to serve) and heat to a simmer in a large saucepan. Press on the solids gently to release broth and then discard all the fish bones and seasonings. Strain the broth well through a colander and then a fine-meshed sieve.

When the broth is full-flavored, turn off the heat.

If it is not reducing steadily, raise the heat and remove the cover. Snapper and bass are two of the most common options, but you could use bones and. In the case of fish stock, the bones typically include the heads, spines, ribs, and tails of mild, non-oily, white-fleshed fish. Adjust the heat to keep it bubbling gently and cook the broth, with the lid set ajar, for 3 hours or so, until the level of the broth has reduced by about one-quarter. Like all animal-based stocks, fish stock is made by gently simmering bones and scraps of meat, along with aromatic vegetables and herbs.

Cover the pot, leaving it open a crack, and bring the water to a boil. Set the onion halves, cut side down, directly on the grate of a stove burner over a medium flame for several minutes, until dark brown (alternatively, brown the cut sides in a heavy dry skillet.) Drop the browned onions into the stock pot along with all the other broth ingredients. Set over low-medium flame to heat gradually. Rinse all the fish trimmings, put them in the stock pot and add 6 quarts cold water.

Fish stock with fish heads