Béchamel, a flour-thickened milk sauce, is one of the basic “mother sauces” of classic French cooking. It’s found in pasta dishes such as Lasagne alla Bolognese and is often used in creamed-vegetable recipes.
1Melt butter in a small, heavy saucepan over medium heat until foaming. Add shallots (if using) and sauté 2 minutes. Do not let brown.
2Reduce heat to low, add flour, and whisk until smooth and raw taste is cooked off, about 1 minute. Gradually whisk in milk. Add bay leaf and cook until just thickened, stirring often, about 10 minutes.
3Stir in nutmeg and salt. Season with ground white pepper. Cool sauce slightly. Discard bay leaf before using.