For fish stock: 
2 pounds of fish trimmings: the heads, tails and bones of any firm, white-fleshed
fish 
6 cups water 
1 large onion, peeled and coarsely chopped 
1 medium-sized bay leaf, crumbled 
6 whole black peppercorns 
1 teaspoon salt 	

Fish Stew: 
one-quarter cup olive or vegetable oil 
1 cup coarsely chopped onions 
1 tablespoon finely chopped garlic 
3 medium, ripe tomatoes, chopped and pureed in a blender or 1 cup canned, pureed
tomatoes 
1 cup dry white wine 
2 tablespoons finely chopped fresh parsley 
(2) one and one-half pound pre-cooked Dungeness Crabs 
3 dozen large mussels in shells 
2 dozen small, hard-shell clams in shells 
2 pounds fresh halibut or ling cod steaks, cut into 8 equal portions 
8 prawns 
one-half teaspoon salt 
Pinch of dry thyme or oregano (optional) 
1. To prepare the fish stock, combine the fish trimmings and water in a 4-to-5
quart stainless steel pot and bring to a boil over high heat, skimming off the foam
and scum that rise to the surface. Add the onion, bay leaf, peppercorns and one
teaspoon of salt, reduce the heat to low and simmer partially covered for 20
minutes.
2. Strain the contents of the pot through a fine sieve into a bowl, pressing down
hard on the fish trimmings with the back of a spoon to extract the juices.
Measure and reserve 4 cups of the fish stock.
3. Wash the pot, add the oil and heat it over moderated heat until a light haze
forms above it. Add onion and the garlic, stirring frequently. Cook for about five
minutes, until the onions are soft and translucent but not brown.
4. Stir in reserved fish stock, tomato puree, wine and parsley, and bring to a full
boil over high heat. Reduce heat and simmer partially covered for 15 minutes.
5. You can save time and effort by having your butcher crack and clean crab for
you. To clean it yourself: hold a crab tightly in one hand, lift off the top shell and
discard it. Pull out the spongy gray lungs from each side and scrape out the
intestines in the center. Place the crab on its back and, with the point of a small
sharp knife, pry off the pointed flap or apron. Cut away the head just behind the
eyes. With a cleaver or heavy knife, cut the crab into quarters. Set crabs aside.
6. Under cold running water, scrub the mussels and clams thoroughly with a stiff
brush or soapless steelmesh scouring pad, and remove the black ropelike tufts
from the mussels. Season the halibut or ling cod on both sides with one-half
teaspoon of salt. Set the mussels, clams and cod aside.
7. To assemble the cioppino, arrange the pieces of crab in the bottom of a 6-to-8
quart enameled casserole. Lay the mussels and clams on top and pour in the tomato
mixture. Bring to a boil over high heat, reduce the heat to low, cover tightly and
cook for 10 minutes. Add the halibut or ling cod and prawns.
8. Cover the casserole again and continue to cook for 8 to 10 minutes longer. The
ciappino is done when the mussel and clam shells have opened and the fish flakes
easily when prodded gently with a fork. Discard any mussels or clams that remain
closed.
9. Sprinkle a pinch of dry thyme or oregano on top. Serve at once from the
casserole, or spoon the cod and shellfish into a large heated tureen and pour the
broth over them. Serve with sour dough or garlic bread.