How to make Bechamel sauce with hot milk

[ML5]

With a Bechamel sauce I was wondering if I heat up milk first & make the roux in separate pot do I take hot milk off the gas and mix in the Roux or is it best to keep milk heating and mix in the Roux

Always add the milk to the roux gradually, you’ll end up with a lumpy mess is you add the roux to the milk.