The best and fail proof white sauce recipe with video. White sauce or Bechamel Sauce is commonly used in Pasta dishes, lasagne and also for fish/chicken.
Heat butter (or olive oil) in a pan.
Add flour and stir for a minute or until the raw smell disappears. Mixture should be without any dry flour. If you feel the flour is more, then quickly add some more butter to dissolve the flour into a smooth mixture.
This is roux and can be taken out and stored to be used later for thickening soups or gravies or to make white sauce later.
To continue to make white sauce, slowly add hot milk in the pan, use a balloon whisk to whisk everything together.
Keep whisking till the sauce thickens and starts bubbling. Since the milk is already hot, it will not take much time for the sauce to thicken.
Once a boil comes and the sauce is sufficiently thick, switch off the gas. You can season it as per the dish you use the white sauce in.