Flour is the thickener that may be found the most easily in most kitchens. Slurry, which is made by whisking together equal parts of flour and water, is one option for thickening a sauce that is too thin. Another option is beurre manie, which is made by kneading together equal parts of softened butter and flour to form a paste. Both of these options are excellent thickeners for rich and creamy sauces, such as Breakfast Burrito Sauce.