Filé is a spice made from powdered sassafras leaves. Some people use it as a thickening agent instead of okra, or in dishes that don't call for okra. It's one of the truly unique aspects of Cajun cooking.
May I suggest jalapeño corn bread with your jambalaya? And serve the jambalaya over rice, by the way. Steamed white rice is fine, but dirty rice would be even better.