The following is a suggestion of the types of seafood you can use in this dish. Feel free to substitute your favorites. Use a variety - a total of about 2 - 2 1/2 lbs. I usually use 1 lb of fish fillets like halibut, pollack or any mild firm fish, skin removed. I whole bag of fresh mussels in their shells - debeareded and cleaned well to remove dirt, 1/2 lb raw shrimp - deveined and peeled, 1/2 lb imitation crab and 1 can chopped clams with their juice. You could use scallops, monk fish, canned or fresh crab- picked clean.
Saute onion, peppers, celery, carrot and garlic in olive oil until soft in a large kettle, stock pot or Dutch oven (that can go on the stove).
Stir in tomatoes, tomato sauce, basil, bay leaf, salt and pepper; heat to boiling; reduce heat; cover and simmer 1 hour on very slow simmer.
Discard bay leaf (You can use a little more diced tomatoes with their liquid if the sauce is too thick, or add more wine or clam juice. Sauce will be thin. It should NOT be as thick as spaghetti sauce.
While sauce simmers, cut chunks of filleted fish off of skin into serving size pieces (about 1-2 inch cubes).
Using a stiff brush, thoroughly scrub the mussels, cutting off their "beards", or the clams, under running water to remove any residue of mud and sand.
Stir wine or clam juice into sauce in kettle. Add fish chunks, shrimp and scallops. Simmer, covered, for 5-10 minutes longer, until shrimp just turns pink. Do Not over cook.
Place mussels or clams in a layer on top of fish in kettle; cover. Steam 5-10 minutes, or until the shells are fully opened and fish flakes easily. (Discard any unopened mussels or clams). If using canned clams, just open can and dump.
Ladle into soup plates or bowls. Sprinkle with parsley. Serve with sourdough bread, or crusty French or Italian bread.
Serving suggestion: Ladle into large bowls with about 3/4 cups cooked spaghetti in bottom. (This is how I serve it.)