Whenever I am shopping for groceries, I think of that line from TS Eliot's poem, "Love Song for Alfred Proufrock," which goes, " In a minute there is time / For decisions and revisions which a minute will reverse."
Decisons and revisions. Broccoli rabe instead of bok choy, mussels instead of clams, polenta instead of porridge. Part of the fun of cooking is working with what you have.
Yet fish head's soup just wouldn't be the same, or even close to it, without a good fish head. You could use the whole fish, or a meaty fillet, but then you couldn't enjoy the diversity of textures and tastes to be gotten in one head. The gelatinous eyeballs, which are fatty-tasting, slippery little suckers. The cheek meat, which is often denser and finer in texture than the rest of the fish. Sections that are neither strictly fish flesh nor fat, but are spongy and pudding-like. Even cartilage, which we normally associate with poultry and pigs instead of seafood, but which can be found in some quantity in a fish's head. And if you make friends with your fishmonger, you'll probably get the rest of the fish frame, too.
In some cuisines, soups with whole fish heads floating about in a soup tureen are perfectly acceptable, even preferred. My Chinese mother wouldn't dream of deboning a fish head. She'd simmer the head with pickled greens and rice wine, add in some noodles, and serve it forth. The fun would be in excavating the fish yourself and using your chopsticks to pluck out succulent morsels.
But not everyone wants to put in the work to reap his or her reward. Some lazy people—I mean, some people—just want to eat their soup out of a bowl with a spoon. This is nice too, on a wintry day when you want a steadying meal and you want to imbibe your soup without having to worry about distractions.
For a deboned fish head's soup, I like salmon heads. You can use any fish head you like, so long as it's large and meaty enough to be worth your time, but if you use salmon heads, consider dill and cream. The procedure is easy enough—sauté some onions or leeks, add the salmon heads and dill and some potatoes or other vegetables, if you like. Simmer, then separate the fish meat from the bones and reintroduce the morsels of tender salmon to the soup, along with more dill and cream. The taste of the stock is fishy without being too overwhelming, especially since it's enriched with cream.
That's the only catch: as the cook, you have to be willing to do the work, to stand over a pile of steaming-hot fish heads once simmered and sift through the detritus. There's some satisfaction in the work of creating order among chaos, but it's tedious too. It lends new meaning to the notion of cooking with love. If you love the people you serve, or simply don't want to injure them, then you want to do a thorough job of picking through the bones. You want to use the utmost care when extricating the eyeballs and the cartilage from the skeleton. There may be people at your table who like such things, even prefer them to plain old fish flesh.