A mushroom primer, from buying to cooking

They are a singularly unprepossessing bunch, mushrooms. Dun-colored, ragged, misshapen. Botanically, they are somewhere between a rock and a plant. But there are few other ingredients that can imbue even the simplest dish with such deep, rich savor.

There's no better time of year than winter to include mushrooms in your recipe repertoire, and local markets have risen to the task of making them available. Not too long ago, the only mushroom you could find was the little white button. Now cremini, portobellos and shiitake are fairly standard, and specialty markets often stock even more exotic varieties.

Wild and not so wild

The term "wild" is used these days to refer to anything that isn't a white mushroom. In truth, the overwhelming majority of mushrooms at the market are cultivated on farms, not gathered in the wild. Moreover, common white, cremini and portobello mushrooms are all the same species, Agaricus bisporus.

The only difference between white mushrooms (also called buttons or champignons) and cremini (also called crimini and baby bellas) is that the latter are brown and more flavorful. When a cremini grows to maturity, with a big cap and exposed gills, it is called a portobello (or a portobella, portabella or other corruptions of its made-up Italian name).

The most common Asian mushroom in America, the shiitake, is also cultivated, as are enoki, the skinny little white ones that come all stuck together. Other, less common cultivated mushrooms include the oyster and the king (or king oyster or king trumpet) mushroom, a fat-stemmed, little-capped variety that's increasingly seen in Asian and specialty markets.

Truly wild mushrooms are rarely seen on supermarket shelves, but you may come across them, in their season, at specialty grocers and farmers markets. The most commonly encountered fresh wild mushrooms are porcini (also called boletus or cèpes), chanterelles, morels and maitakes.

Dried mushrooms

One relatively thrifty way to get the incomparable flavor of wild mushrooms into your food is to use them in their dried form. Most specialty markets and Italian grocers sell dried porcini mushrooms, and most supermarkets sell little white tubs of Kirsch-brand dried imported mushrooms. Dried shiitake mushrooms are sold in all Asian markets in an array of price ranges, depending on quality.

To use dried mushrooms, first swish them around in some cold water to remove any dirt, then put them in a large, heatproof bowl and cover with a cup or two of boiling water. The mushrooms will take anywhere from 15 to 30 minutes to soften. Extract mushrooms from soaking liquid, rinse, then slice or chop as desired. The soaking liquid is now full of mushroom flavor and should be used in place of an equal amount of water or broth in whatever recipe you are following. A fair amount of grit will have sunk to the bottom of the bowl, so either be very careful when you pour it out, or strain the liquid through one layer of a two-ply paper towel.

Buying, storing and cleaning mushrooms

Look for mushrooms that are smooth and unblemished and, if they are white or cremini, with tightly closed caps that expose no gills. Many mushrooms these days are prepackaged; do your best to assess them through the plastic wrap. If you are planning to keep the mushrooms for a few days, let them breathe: place in a colander topped with paper towel, or in a brown paper bag. Most importantly, do not clean them until just before you plan to use them.

Much ink has been spilled over cleaning mushrooms. There's the injunction against ever soaking them lest they absorb too much water, and the merits of using a dedicated mushroom brush.

Relax, they're just mushrooms. If they are really dirty, knock off excess dirt by banging them gently on a hard surface. Then run each one under cool running water, using your fingers to wipe off any surface dirt. If it's stubborn, use a wadded up paper towel. Done.

I trim off and discard the very bottoms of the stems of white and cremini mushrooms. Shiitake mushroom stems are unpalatable; cut them off and throw them out. I am perfectly happy to buy presliced mushrooms, which require no cleaning or trimming.

The easiest, most versatile way to cook mushrooms

Cut mushrooms -- any combination of varieties -- into roughly same-size pieces. Place in a wide frying pan with a little olive oil and a little more water. (For 1 1/2 pounds of mushrooms, use 1/4 cup of water and 2 tablespoons olive oil.) Season aggressively with salt and pepper and feel free to throw in a few sprigs of thyme and/or rosemary and a couple of lightly crushed cloves of garlic. Cover the pan and place over high heat. Shake the pan every so often, and when you hear it start to simmer, turn heat down to medium high.

After about 8 minutes, the mushrooms will have given up most of their liquid. Turn up the heat and continue to cook until almost all the liquid has cooked off. Fish out the herbs and garlic and correct seasoning. Sprinkle with minced parsley.

At this point you can:

* Serve as a side dish with any grilled or roasted meat.

* Heat up with a little cream and serve as an even better side dish.

* Fill an omelet or make a mushroom scramble.

* Spoon into warmed tortillas with some sliced onion and anything else you might have on hand to make tacos de setas, mushroom tacos.

* Toss with pasta (plus some pasta-cooking water) and a good grating of Parmesan or pecorino and more olive oil.

* Add a can of peeled Italian tomatoes to the pan and simmer it until you have a nice mushroom sauce.

* Make soup by adding chicken or vegetable broth to the mushrooms, and perhaps some chopped vegetables and/or cooked rice (or barley). For a creamy soup, puree a portion in the blender (or use an immersion blender).