A good béchamel large enough for 1 – 9 x 9 deep baking dish:
4-4 1/2 cups milk,
1/2 cup butter
1/2 cup all-purpose flour
A couple grates of nutmeg
salt and freshly ground black or white pepper
Melt the butter with the flour whisking until smooth and allow it to cook for at least 3 minutes then add all of the milk whisking constantly until it thickens. Turn the heat to low and allow the béchamel to cook for 7 minutes, stirring often…this is where I never leave it alone and I just keep the whisk going as I know I will ruin the sauce if I walk away… season with salt, pepper and a few grates of nutmeg.