roux is a sauce base. Oil and flour slowly cooked until it turns a chocolate brown. However if you try to hurry it the flour will burn giving the base a very bitter burnt taste.

It's easy to make if you have 45 minutes that you want to sit and stir a skillet constantly. That's why I buy it.

It is located on the same aisle as the spices and salad dressings here. Kroger has it and I am sure other supermarkets do as well.