Step 1

Prepare all ingredients and set aside. Heat the milk using the microwave or stovetop until hot but not boiling and set aside.

Step 2

Place a medium saucepan over medium-low heat. Add the butter and let it melt completely. Immediately add the flour and whisk rapidly to form a bubbly paste, less than 1 minute.

Step 3

Add the milk 1/3 cup at a time, whisking continuously until the sauce starts thickening before adding the next batch. (If this takes longer than a minute or two, raise the heat slightly.) Scrape the bottom and sides of the saucepan with the whisk to prevent sticking.

Step 4

Once all of the milk has been added, set the whisk aside and switch to a wooden spoon. Stir until the sauce starts bubble or becomes thick enough to coat the back of the spoon.

Step 5

Remove the saucepan from the heat. Stir in the cheese and optional seasonings until the sauce is creamy and smooth. Serve immediately.