Roux is king in the kitchen.
The length of time that you cook the roux determines its color, from blond to deep brown, and its flavor; a deeply browned roux, often used in Cajun and Creole cooking, has the aroma and flavor of toasted pecans. A lighter roux, by contrast, is cooked just enough to eliminate a raw flour taste in a finished dish, but has more thickening power than its darker brethren.
Think of roux as a more flavorful alternative to cornstarch, and keep in mind the following ratio: a roux is made from one part fat to one part flour by weight. The fat used is often butter, but darker roux is usually made with vegetable or olive oil, which can withstand the longer cooking time without burning. Lard and beef fat can also be used.
Sometimes it’s good to be king.