Now we need to make a roux. "Roux" is the French word for "brown," and brown describes a roux in color. A roux is a base for gravies, soups, etouffee, gumbo and many other Cajun and French dishes. It serves as a thickener, binder and flavoring. Any cook who has made gravy from pan drippings, flour and milk has made a sort of roux. The principles are very similar. With a roux, however, only flour and fat are used.
1st rule of roux is patience. It takes time to reach the desired stage of brown and not burned and you should be diligent to stir the roux constantly. Cooking slowly and evenly is a must to prevent burning.
2nd rule of roux is to use a heavy pot, a whisk and a wooden spoon. The pot should be heavy and not have any hot spots. A dutch oven or iron skillet works best. A wooden spoon is great to use because it does not impart a metallic flavor to the roux.Melt the butter in a medium saucepan on medium heat. Using a whisk, stir in flour; cook, stirring until bubbly. Gradually add milk and whisk to make sure there are no lumps. You can switch to a wooden spoon now and cook over medium heat, stirring occasionally until sauce thickens. Remove from heat; set aside to cool, about 15-20 minutes.
3rd rule of roux is we don’t talk about how difficult roux can be – we just put our big girl panties on and make roux.
Then pour in the remaining batter and smooth the surface.