01 -
In a small saucepan, gently warm the milk over low heat. Do not bring it to a boil.
02 -
In a medium-sized saucepan, melt the unsalted butter over medium heat. Add the all-purpose flour to the melted butter, whisking constantly to form a smooth paste. Cook for 1-2 minutes, taking care not to let it brown.
03 -
Gradually add the warm milk to the roux, whisking continuously to prevent lumps from forming. Continue to cook over medium-low heat, stirring often, until the sauce thickens to your desired consistency. This should take about 5-7 minutes.
04 -
Stir in the salt, white pepper, and optional nutmeg. Taste and adjust the seasoning as needed.