Béchamel is a home-economics-class sauce. You learn to make it, but you never conceive of using it again. But a good béchamel has its place in the world, though mostly as a supporting player rather than a star. You can’t make a cheese soufflé without béchamel, some delicious lasagnas are made moist with béchamel (called besciamella in Italian), and real mac and cheese is all about the sauce, which starts with béchamel. Many béchamels are made with only milk, but I’m adding 30 percent cream because I like the depth of flavor it imparts. Don’t be tempted to add a lot of nutmeg. It’s fun to grate, but it can call unwanted attention to itself.
Storage: Refrigerate in an airtight container for up to 3 days. The sauce does not freeze well.
In a medium saucepan, combine the butter and flour over medium-high heat and whisk to blend as the butter melts. Cook, whisking a lot, for about 1 minute. This will give the flour a nutty, rather than floury, flavor.
Pull the pan off the heat and pour in about ¼ cup of the milk. Whisk like crazy to form a smooth paste, then whisk in the remaining 1 cup milk and the cream.
Return the pan to medium-high heat and bring to a simmer, whisking frequently and making sure to get into the angles of the pan where the thick roux can accumulate.
Simmer, giving the sauce an occasional whisk, until smooth and glossy and no taste of flour remains, 8-10 minutes. As it simmers, be sure to scrape down the sides of the pan where the sauce builds up and whisk into the sauce; otherwise you will end up with lumps.
Add the salt, several grinds of pepper, and the nutmeg, then taste and adjust the seasoning. Serve right away or keep warm over low heat.
Variation: Add ¼ yellow onion and 1 fresh thyme sprig after whisking in the milk and cream. Remove before serving.