The carcasses (head and bones) of any white-fleshed fish may be used to make a flavorful fish stock—monkfish, snapper, cod, haddock, weakfish, whatever is available. Do not use oily fish such as bluefish, mackerel, or salmon, however, because the flavor is too strong. Fish or seafood stock should never be cooked for as long as a meat stock, as overcooking will make it bitter.
MAKES 6 TO 7 CUPS FISH STOCK
Head and bones of one 4- to 6-pound fish, preferably haddock, cod, or snapper
2 or 3 bay leaves
1 medium onion, halved
1 teaspoon whole black peppercorns
About 15 flat-leaf parsley sprigs (⅓ to ½ bunch parsley)
1 cup dry white wine
6 cups water
Sea salt and freshly ground white pepper
Combine the fish, bay leaves, onion, peppercorns, parsley, wine, and water in a heavy stockpot or soup kettle and bring slowly to a boil over medium-low heat. Cover, turn the heat down to a bare simmer, and continue cooking for 45 minutes. Strain the stock through a double layer of cheesecloth in a colander and discard the solids. Taste and adjust the seasoning, adding salt and white pepper to taste, keeping in mind that the salt will be concentrated if the stock must later be reduced.