Your own homemade stock is the ideal thing. Even if you start with a canned chicken stock, or use clam juice as a
substitute for seafood stock, you still ought to consider a few kitchen maneuvers to add some depth and character. (Some folks will even use just water and beer in place of stock for a long-cooking gumbo. I'm not saying that this doesn't work, but we're aiming here for the extra layers of flavor we can get from a slowly-simmered stock.)
For poultry stock, we want a rich, dark-brown stock. One excellent trick is to use the oven to prepare the
ingredients for the stock pot. If you're making stock from scratch, first roast the bones in a very hot oven until
well-browned. A mix of poultry bones is terrific -- e.g. chicken,
turkey and duck. Put the roasted bones in your stock pot and cover with water; then, leaving only a tiny amount of fat in the roasting pan, put your roughly-chopped onions (skins on) and carrots in there, and roast them until well-browned, too. Now you can add them to the stock pot, along with plenty of water to cover everything to a depth of at least a couple of
inches; also add your celery, peppercorns, bay leaf, and herbs. Deglaze the roasting pan, scraping up the brown bits from the bottom, and also add this to your stock pot. Bring the
stock pot to a boil, skimming the scum off the surface until no more forms, then reduce the heat. Simmer slowly for
six to eight hours. Finally, strain, cool in shallow pans, remove all fat from the surface, and refrigerate.
For same-day preparation, if you don't already have your own homemade poultry stock, you can start with canned chicken stock. Be sure to use a low-sodium stock so that you can control the saltiness of the finished product. You can use some of the above instructions, including the roasted onions and carrots, to greatly improve on the canned stock. Once your onions and carrots are well-browned, add them to the canned stock,along with your celery, peppercorns, bay leaf, and herbs; then simmer slowly. You'll still need to start early, but this can at least be done earlier the same day you make your gumbo. Strain the stock before starting to cook the roux, since you won't get another chance after that.
For seafood stocks, of course, we don't roast anything. When preparing seafood stock, be sure to wash your fish bones thoroughly so that the stock doesn't get unpleasantly fishy.
Avoid dark-fleshed or oily-fleshed fish when making stock. On the other hand, crustaceans are especially good for this purpose, and your crawfish shells,shrimp shells, crab carcasses and even a lobster carcass or two will certainly build you a fine stock. You'll want to put some roughly-chopped onions and celery, peppercorns, a sliced lemon, a few crushed garlic cloves, and
some shrimp and crab boil in your stock pot. Once you've brought it to a boil and skimmed away the scum that rises to the top, simmer slowly for two or three hours; then strain well, cool in shallow pans, remove all fat from the surface, and refrigerate.
For same-day preparation, in the absence of your own homemade seafood stock, clam juice is probably the best alternative. You might consider using a mixture of clam juice and water as the basis for a quick seafood stock,including your shrimp shells, fish bones and what have you, and otherwise more or less following the instructions in the previous paragraph. Be sure to strain, cool and remove surface fat before you start cooking
the roux.
I'm not offering specific proportions for making stocks from scratch. You can base your proportions on what you find in just about any cookbook, adjusting the recipe to fit what you've got on hand. Thyme and parsley are the herbs most often used for the poultry stock. If you don't have fresh herbs, you can use dried herbs, but wait until you're done skimming the surface of the stock pot to add them. Naturally, many variations are possible. For instance, I often add a few whole cloves to the stockpot. The best idea for these standard stocks is to make quite a bit at a time, then refrigerate overnight, remove the fat that rises to the surface, and freeze the defatted stock in jars. Then you'll be all set to make gumbo the next time the mood comes over you!
