Instant dissolving flour is a real plus for thickening without added fat. It is a type of flour that has been pregelatinized, which results in a flour that easily dissolves in liquid without forming lumps.
Dissolve 2 tablespoons instant dissolving flour in 1/4 cup liquid (water, broth, milk or other cooking liquid). Stir into soup, sauce or other dish to thicken. If additional thickening is desired, remove liquid mixture from heat, shake additional instant dissolving flour into liquid and stir to dissolve. Return mixture to heat and cook 1 minute.