Béchamel, or besciamella in Italian, is a fundamental white sauce, familiar for its many uses in European cuisines. Basically, it’s just hot milk or cream added to a roux of butter and flour and stirred together over heat until it thickens. It’s easy enough to make, but it does require attention and it’s not something that can be made ahead and held for more than a couple of hours. We use béchamel as a sauce layer in most lasagnas and also in baked pasta dishes such as pasta al forno or mac and cheese, but we steep the milk with aromatics to add more flavor to the final sauce.
To make the béchamel, simply combine whole milk in a saucepan with aromatics and bring to a simmer, then remove from the heat and let steep for an hour while the milk absorbs the flavors. When the milk is ready, strain out the added flavorings and measure the milk. You will find that the milk has reduced in quantity since the seasoning vegetables will have absorbed a certain amount.
The following recipe, calling for 6 cups of milk, will make 4 to 5 cups of béchamel (some of the liquid inevitably evaporates during the cooking process). If the recipe calls for a lesser quantity, simply decrease the amount of milk proportionately. That is, if the recipe requires 3 to 4 cups of béchamel, make it with 4½ cups of milk, adding a little less butter and flour to the roux. In the end, the sauce should be the consistency of thick, heavy cream but not of sour cream and certainly not of library paste. If it is too thick, add more milk, a little at a time, until it is the right consistency; if it’s too thin, keep cooking it down until it has thickened properly.
MAKES 4 TO 5 CUPS BÉCHAMEL
6 cups (1½ quarts) whole milk
1 medium onion, cut in half
1 leek, split, cleaned, and cut into 2-inch chunks
2 or 3 bay leaves
1 teaspoon whole black peppercorns
2 garlic cloves, peeled but left whole
3 or 4 fresh thyme sprigs
2 medium celery stalks, cut into 4-inch pieces
Several flat-leaf parsley sprigs
4 tablespoons (½ stick) unsalted butter
¼ cup unbleached all-purpose flour
¾ cup freshly grated parmigiano-reggiano
Sea salt
Freshly grated nutmeg
Combine the milk, onion, leek, bay leaves, peppercorns, garlic, thyme, celery, and parsley in a saucepan. Set over medium heat and bring just to the simmering point, then remove from the heat and set aside, covered, for at least 1 hour while the milk absorbs the aromatic flavors. When the milk is ready, strain out the added flavorings and measure 5 cups milk. Return the 5 cups to the saucepan and heat just to the simmering point. Turn off the heat but keep the milk warm while you make the béchamel.
In a separate saucepan large enough to hold all the milk, melt the butter and stir in the flour with a wooden spoon, stirring constantly and smoothing out any lumps. Cook for about 3 minutes, or until you no longer smell the odor of raw flour. Now start adding the hot flavored milk, about ½ cup at a time, stirring after each addition to amalgamate the milk with the flour-butter paste thoroughly before adding more. At a certain point, you will find it easier to switch to a wire whisk instead of the spoon. Keep adding the milk and stirring until all 5 cups of milk have been added. Stir in the parmigiano with a pinch of salt and several gratings of nutmeg and continue cooking and stirring for about 5 minutes, or until the sauce has thickened to the desired consistency. The sauce should be smooth and velvety in texture.
If you cannot use the sauce immediately, remove it from the heat but keep it warm and settle a sheet of plastic wrap right on the top of the sauce to keep a skin from forming.