Learn all about how to cook and eat seafood gumbo. Get recipes, fun information and more. A typical seafood gumbo contains one or more kinds of crab, shrimp, fish, oysters or crayfish. Gumbos can be broadly divided between the use of okra as a thickener, and recipes using filé powder in that role. Roux may be added to either and it is quite common for roux to be the sole thickening agent and base for the stew.