Filé, also known as filé powder or gumbo filé, is a seasoning and thickening agent made from dried, finely ground sassafras (Sassafras albidum) leaves. It is now used almost exclusively in gumbo as a thickening flavoring agent or added as a condiment.

Commercially produced filé is often olive-gray, green-brown, or moss colored, but artisanal filé picked during peak time is often a bright or emerald green and highly aromatic. Sassafras selectively picked late in the season can produce a rare, red-colored filé. When added early in a soup, filé thickens the dish, adding a viscous, slimy, and stringy consistency that resembles ropes when poured. (The word “filé” is French, meaning “threaded” or “stingy,” which describes this property as a thickening agent.) Filé can also be added as seasoning to a gumbo, soup, or stew after reducing the heat, which gives a sweet, earthy, peppery, and thyme-like flavor while keeping the dish from taking on the “ropy” characteristics. Most often people sprinkle it on a dish as a finishing garnish. Louisiana Creole and Cajun restaurants serving gumbo often include filé in their table condiments. While filé is synonymous with finely ground sassafras leaves, sometimes a blend will consist of other herbs like bay leaves, oregano, thyme, and basil.

Filé is one of three common thickening agents for gumbo, the others being okra and the popular flour roux. Although these can be combined, historical documents suggest that filé gumbos and okra gumbos were traditionally distinct and based on the limited seasonal availability of okra. Filé gumbo can also be made without a flour roux, which is common among Houma people. In the past many Choctaw foods used powdered sassafras.

The sassafras tree (iti kʋfi in Choctaw) has different organs, each with seasonal flavor profiles. Choctaw people developed multiple medicinal and food uses for their uses. These include harvesting the plant’s slightly spicy and subtly vanilla-anise-licorice-flavored root bark in the winter or early spring for teas (a forerunner of root beer) and gathering the bark and the leaves for teas and flavorings in late spring through early fall.

Filé made from fresh green sassafras dried in the dark has a lemony-coriander flavor profile with a grassy undertone. Commercial sassafras tends toward a duller green color that comes from drying with exposure to sunlight and oxidation from mass processing. In the fall red sassafras is made from red leaves and has a different flavor due to the absence of chlorophyll.