The first step in making a roux is to brown the meat called for in the recipe in a Dutch oven, and then pour the drippings into a liquid measuring cup. Next, add enough vegetable oil to measure ½ cup—you’ll probably need to add about ¼ to 1/3 cup.
Add the oil mixture to a Dutch oven, and place over medium heat until hot. Add the flour, and cook, stirring constantly with a wooden spoon. The mixture will bubble a little and look like it’s simmering. It will start turning light brown after about 10 minutes—this is a “blond” or “medium-brown roux” and can be used for sauces and gravies. To get a “black” or dark brown roux, you’ll need to cook the mixture about 20 to 30 minutes or until the roux is chocolate-colored. Don’t try to rush the process—if the roux burns, throw it out and start again.
When you get the roux to the dark brown stage, proceed with the rest of the recipe.