The easiest way to ruin a chowder is to overcook the seafood. Scallops dry out and become fibrous. Lobster dries out, too, and loses much of its flavor. Clams, by nature nearly as tender as oysters, become as tough as the sole of your shoe. Chowder fish is the most ignominiously treated of all. Beyond flaking it disintegrates, and your chowder becomes a sea-flavored gruel with potatoes and onions in it. Be very careful with fish. The method that follows will help avoid overcooking and also persuade your cod or haddock or hake to release its savory fat into the broth.
This chowder begins with a stock and there are several options. One is to make a broth by steaming mussels, and in my opinion, it is the best to be made. Clams make a good broth, too, a stronger one, but it is often murky, a kind of fathomless gray. The recipe which follows calls for a fish fumet, a stock made with inexpensive fish racks. If racks are not available, you may have to resort to bottled clam juice. Better still, use a combination of clam juice and a court bouillon, a vegetable stock commonly used to poach fish and very much like a fumet without the fish bones.
3 pounds racks from white-fleshed fish (never oily) with or without heads
1 1/2 quarts water
1 bottle white wine
2 teaspoons salt
2 sticks celery, chopped
2 carrots, peeled and chopped
1 large onion, chopped
juice of 1/2 lemon
1/2 teaspoon dried thyme
1/2 teaspoon dried tarragon
1/2 cup chopped parsley, preferably flat-leaf (Italian) parsley
1 teaspoon whole black peppercorns
Rinse the racks thoroughly under running water, cleaning them of even the slightest residue of innards or blood, which will ruin the stock. Break the racks into three or four sections and place them, along with the water, wine, and salt, in a large pot. Bring slowly to a boil and skim the scum that rises to the surface.
Add the remaining ingredients, except the peppercorns, bring to a boil again, and cook rapidly for 15 minutes. Add the peppercorns and continue to boil for another 15 minutes. Pour through a fine strainer and cool.