As a first step to prepare our bechamel sauce, melt the butter over a low flame in a small long-handled saucepan, taking care not to fry it.

Then add the flour and mix vigorously to make it incorporate well into the butter. Continuing to mix, let it cook over a low flame for about 2 minutes; the mixture must gain flavor without browning so it must remain white in color.

Then remove the pan from the heat and pour the warm milk. Put it back on the heat and mix well with a whisk to make the sauce thicken.

At this point, salt the sauce and let it cook for about ten minutes, stirring often. The bechamel sauce is now ready to be used.

Useful tips:

To cool the sauce, pour teaspoons of cold milk on the surface.

If lumps form during cooking, just pass the sauce through a colander.

The bechamel sauce can be safely stored in the refrigerator for about 2-3 days.