Gumbo file, also known as file powder, is a spice made from dried sassafras leaves. The leaves of this tree are dried and grounded to create gumbo file or file powder which is typically used as thickening agent for broths and soups. The use of gumbo file is famous in Creole and Cajun cuisines which can be found in various parts of Louisiana and other southern US states like Alabama and Mississippi among others.

Sassafras leaves were already used in the past as spice and flavoring for soup bases and broths. The leaves are dried in the sun and are crushed before they are used for soups. The fibers of the sassafras leaves are the ones that thicken the soup and give it a distinct flavor and texture. At present times, gumbo file can be found in its powder form. As with many other spices, gumbo file is typically stored in air-tight containers to protect them from easy decay and retain their cooling scent. Many people like the addition of gumbo file in powder form to various soup preparations because of its unique cooling aroma similar to the scent of eucalyptus. Most people also add gumbo file to soups and stews to improve its texture and consistency. Instead of having to use okra for its thickening purpose, the use of gumbo file is a good alternative. For traditionalists, gumbo file in the form of whole dried sassafras leaves are also available in some public markets.

In most cooking techniques, a sprinkle of gumbo file is added as the last step to thicken the soup or sauce base. There are cases though that gumbo file is used as some kind of condiment just like salt or pepper. In this latter case, people will just sprinkle gumbo file or file powder onto their stews while they are enjoying it. More gumbo file may be added as one pleases and prefers.