Every once in a while, when I get the feeling that my arteries are still
too flexible and my heart isn't working hard enough pumping blood, I'll
make a large skillet of sawmill gravy and pour it over biscuits for
breakfast. The recipe I follow says, as do all the other recipes I've seen
that involve making a white sauce, that once you have the roux the color
you want, you should take the pan off the heat to add the milk. I've often
wondered why that is and what would happen if you added the milk directly
to the pan containing the roux while it's still on the burner. Rather than
risk seven years' bad luck or something similar trying it, I thought I'd
ask. Can any of the RFC intelligentsia enlighten me?