Non-Fat or "Dry" Roux
From the American Institute for Cancer Research

Put 1/2 cup flour in non-stick skillet over low-to-medium heat. Stir frequently at first, then constantly as flour begins to toast and take on color. Occasionally shake pan to help keep flour moving and color evenly. Flour can burn easily, so watch heat level and adjust as needed. Be prepared to lift pan away from burner if necessary to prevent flour from burning.

Once flour begins to cook, it will color quickly, so pay close attention. At 5 to 7 minutes, flour will turn a medium brown – the color of light brown sugar or peanut butter. Do not allow flour to turn darker – dry roux turns darker when liquid is added later. Transfer flour to a small bowl and allow to cool. Transfer to tightly covered jar and store in refrigerator, where it will keep several weeks.

When making gumbo, sprinkle dry roux over sautéed vegetables, mix in well, then slowly add bouillon, stirring constantly, to create a smooth, lump-free mixture.