The common use of this “mother sauce” is in lasagna or cannelloni, but you can get creative and use it to bring flavor to other dishes as well, like with cooked vegetables, as the base for a creamy soup or added to macaroni and cheese.
Heat the milk in a saucepan over medium heat until just about to boil. You’ll know it’s ready if it sends up a little steam when you stir it.
While the milk is heating, melt the butter in another saucepan over medium low heat.
Slowly add the flour to the melted butter, whisking continuously, to create a smooth mixture. Keep whisking for another minute to let the roux cook. Be careful not to let it brown.
Begin to whisk the milk into the roux slowly, a small ladleful at a time. Be patient and don’t rush. The mixture will be thick and hard to whisk at first, but it will thin out as you add the rest of the milk.
Once all the milk is fully incorporated, season to taste with the salt and pepper. If you want to add nutmeg you can add a generous dash of grated nutmeg at this point.
Keep whisking slowly as the sauce thickens.It will take approximately 12-15 minutes to reach the right density, so don’t worry if your sauce seems too thin at first. It’s ready when it begins to stick to the whisk in a nice thick coat and stirring becomes more difficult.
Remove from heat and use, or let cool completely before storing.