File ', also called gumbo file', is a spice made from dried and ground sassafras leaves. It is used in making gumbos of the Cajun and Creole type and is utilized primarily as a thickener.
When ground, the sassafras leaves have a citrus like aroma and in
addition to adding thickness, it infuses a distinctive flavor you will
love. Many south Louisianans won't have gumbo without it. As in most Cajun homes, my Mother always had a jar of file' on the table when serving gumbo. A teaspoon added to your gumbo in the bowl and stirred in with a little Tabasco sauce makes for a really special dish.
It is generally used sparingly and is added to the bowl after serving. It can be added to the pot of gumbo at the end of cooking but should not be boiled or cooked further as it will loose it's flavor and thickening effect.
File' was in used by the Choctaw Indians when Europeans arrived in Louisiana and probably predates okra as a thickening agent for gumbo. Later it was used when okra was not in season thus contributing to it's popularity.
In modern recipes, file' gumbos use roux as their primary thickener, with file' powder added in the bowl at the time it is served.
Contrary to what some say, file' is not a necessity for making an authentic and fantastic gumbo. But it is a wonderful option to have and should always be available for your family or guests to add at the table. It will surely enhance the eating experience.
For an average size serving of gumbo, start with 1/2 teaspoon of file' served in the bowl and stirred in. Taste. Add more if desired.
A jar of file' will last a year or more in your pantry. It will loose is freshness like any spice after that time. But don't worry it is a very inexpensive spice and can easily be replaced.