What is a Roux? (Cajun & Creole Style) A roux is the heart and soul of Cajun and Creole cooking. a simple mix of fat and flour cooked together until it becomes the color and flavor you want. It’s the base that gives your gumbo, étouffée, gravies, and stews that deep, rich body and that “been-cooking-all-day” taste. The Breakdown • Two ingredients: fat flour • The goal: build flavor, color, and thickness • The rule: don’t rush it! the darker it gets, the more you gotta babysit it • The magic: eve