In Cajun and Creole cooking, what is a roux made by cooking together?

In Cajun and Creole cooking, a roux is made by cooking together fat and flour.

The mixture is heated while stirred, allowing the flour to thicken liquid and develop a deeper toasted flavor. Louisiana cooks may use butter, vegetable oil, or other fats, depending on the dish and the desired color. A roux can range from pale to very dark brown.

Cajun and Creole traditions are particularly known for dark roux, which contributes both body and a roasted flavor to dishes such as gumbo. Darkening the roux reduces some of its thickening power, so cooks balance color, flavor, and texture carefully.

A roux is not the same as a slurry: a slurry mixes starch with cold liquid and is added later. Nor is it simply browned flour. The defining preparation combines flour with fat and cooks them together before additional liquid is incorporated.