Wikipedia Article About File powder on Wikipedia Filé powder, also called gumbo filé, is a spice made from dried and ground sassafras leaves. It is used in the making of some types of gumbo, a thick Cajun soup. It is sprinkled sparingly over gumbo as a flavoring and thickening agent, giving it a distinctive flavor and texture. Mixing okra and filé is considered a cardinal sin in Louisianan cuisine, as filé was originally an okra substitute when okra was not in season.