Hollywood knows: how to make a roux and when.

a roux is used to thicken sauces, usually white sauces.

Take fat (butter or oil) and heat to liquid, medium-low.
add an equal part of starch (usually flour).

cook on medium-low until it smells like nuts or turns a blonde color.

yeah, I'm still trying to figure out what this blog will be about. Things should get more interesting as I get drunker and madder.