In order to make bchamel sauce, one of the foundational sauces of French cooking, you should start with 4 and cups of milk. Make sure the milk has some fat in it; otherwise the texture won’t be right. Place this in a heavy pan. Stick one whole clove into a whole peeled onion, and add this along with a bay leaf to the milk. Simmer this mixture for several minutes in order to perfume the milk with the seasonings.
In the meantime, make a light roux. Take 4 tablespoons of butter and melt it in a heavy-bottomed pan. It is best to do this over medium-high heat. Then add 8 tablespoons of plain all-purpose flour and mix it into the melted butter vigorously. It is important at this point to watch it carefully. The mixture will first look creamy, and then it will become pastier and grainier. When it reaches the pasty and grainy stage, it is time to stop cooking the roux. It should be a light yellow color. Once the roux is made and the milk has been heated and flavored, take a ladle and carefully ladle the milk into the roux, being sure to strain out the onion and bay leaf, and then stir vigorously until the mixture is combined well. Keep adding ladles of milk to the roux and stirring until smooth before adding the next ladle. When either the milk is gone or the sauce is thick enough, season it with salt, white pepper, and nutmeg.