This is a standard bechamel, with a small twist: I use a leek in place of an onion, though a half onion works fine. Bay leaves should be adjusted; a fresh bay leaf is worth a half dozen dead ones.

• Slice large section of leek, long-ways, to expose the center of the leek.
  • pin a bay leaf to the outside of the leek using three cloves;
  • place the bundle into 1 1/4 cups of milk, and simmer over low heat, for fifteen minutes; meanwhile –
• In double boiler, make a two and two roux; quite simply, melt two tablespoons of butter in the double boiler, and slowly whisk in two tablespoons of all purpose flour;
• Strain the milk, and whisk into the roux, slowly;
  • when all the milk is added, simmer, over low heat, with constant attention for about 8 minutes, until thickened considerably.
  • touch-off with salt and pepper (gently)

That’s it. You have a base sauce for innumerable variations, and fantastic as it is.