Gumbo originated in southern Louisiana. It's a dish that can be cooked like a stew or a soup depending on how thick you make it. It is served over rice. The name, gumbo, is thought to come either from “ki ngombo” (African for okra) or “kombo” (Choctaw for file (pronounced "fee-lay")). Either okra or file can be used as a thickener for gumbo. In addition to the thickener, you will need a stock base, meat, vegetables and spices.
Cajun Vs. Creole
There are two types of gumbo, Creole and Cajun, and you add different ingredients depending on which type you are making. Cajun gumbo uses shellfish, sausage or meat and is very spicy due to the addition of cayenne pepper. Creole gumbo has shellfish and tomatoes and is less spicy. Cajun gumbo uses a dark roux or file as a thickener and Creole gumbo uses okra or a light roux.
Stock
The stock used in a gumbo is almost as important as the gumbo itself. A good gumbo stock uses shrimp shells or fish bones with water, carrots, onions, celery and spices. Some spices to include are garlic, cloves, basil, salt and pepper. Let the stock simmer for several hours before using it in your gumbo.
Meat & Shellfish
You can add a wide variety of meat combinations to a gumbo but there are a few general rules to follow. Gumbo can have oysters, shrimp, crab, chicken, duck, squirrel, rabbit, sausage or ham in it. If you do a seafood-based gumbo, you should only add sausage or ham as a meat and a meat-based gumbo only has oysters as a seafood addition. Beef and other pork are never used in traditional gumbos. Add a spicy sausage, such as andouille, if you choose to use sausage in your gumbo.
Vegetables
Nearly all gumbos use what is referred to as the "holy trinity of vegetables": celery, bell peppers and onion. Creole gumbo usually adds tomatoes to the soup and you can strain out the vegetables when you are done cooking if you prefer. Cajun gumbo never has tomatoes and the other vegetables should be left in the gumbo.
Thickener
A roux can be used in either gumbo though Cajun gumbo tends to have a dark roux while Creole’s is lighter. Roux is made from a mix of flour and fat that thickens the gumbo and cooks along with it. The longer you cook the gumbo, the darker the roux. Okra tends to be cooked as a thickener in a seafood gumbo over meat-based gumbos and can be combined with roux. File is a powder added at the end of the cooking process as it can make the gumbo too stringy if used earlier in the cooking process.