Learn How to Make a Roux for gumbo so you get the best rich Cajun flavor. Simply whisk together flour and either melted butter or oil, then simmer until you achieve a white, blonde, light brown, or dark color for all of your thickening needs.
Heat a pan over medium-low heat. Add butter to it and allow it to melt completely.Sprinkle in flour and begin stirring immediately. Stir constantly to keep from burning. This is great to use as a thickener in soups or sauces.