I always liked tomato-based Gumbo.  When I managed Red Lobsters (a long time ago), we made a terrific Seafood Gumbo.  Of course, we always had a lot of Shrimp and clams to put in it.
  For a roux gumbo, try this Country-style one that my stepmother from Louisisana likes:  [As in any good recipe, the amounts and exact ingredients are fluid, not static.  Use what you like, and use what is in season.  When something is in season, that means that it is at its peak time: both the price is lowest, and the quality is at its best.]
 1) Salt water shrimp,  you can buy broken pieces, but be sure to buy uncooked saltwater shrimp (the pre-cooked shrimp will not be as flavorful, as most of the flavor is diluted in the cooking, and we want that flavor to go into the Gumbo and not down the drain at the processing plant).
  2) I like to add some clams, with the clam juice.  Again, the quantity is dependant upon your taste.  For a standard-sized stock pot (1-2 gallons) a couple of 8 oz. cans of Sea Clams is good.  To my taste, a couple more cans is better.
  3) You need to have a base.  Almost all soups start with a chicken base.  In Louisiana, they like to put a couple chicken breasts in the stock pot to cook, breaking up the meat (known as "pickin' chicken") after it has become tender and stringy.  For a gumbo without tomatoes, I would add a beef stock, to make it a little more savory, as well as to darken the base.  A couple cans of "Jellied" or "gelatin added" beef consomme is good for this batch.  The gelatin will help thicken the base, as well.  They are in the soup section at the store.
  4)  At least two # 303 (15.5 oz.) cans of okra.  I prefer Trappey's brand.  Be sure to get the one without tomatoes (they make them both ways), and you may use frozen cut okra instead if you like.  Most of the time Gumbo is made with canned okra, because that is the way it was made for decades before they invented freezing and year-round fresh produce.  For a traditional Gumbo, use the canned stuff.  Remember: gumbo means "Okra Soup", so pile on the okra.  None of these other ingredients are absolutely necessary for Gumbo, but Gumbo IS Okra Soup.
  5)  "Aromatic Vegetables."  In the classic French cooking style, the term "aromatic vegetables" means specifically onions, carrots, and celery.  For our purpose, forget the carrots and I would add less onions, (maybe one medium yellow onion), and some roasted garlic.  If you roast your own garlic, leave the individual lobes of the bulb separated on a sheet pan with the skins still on them, and bake until soft/squishy; cut the ends off and squeeze the resulting garlic out of the skins like toothpaste.  The store-bought prepared garlic is fine also, it is in the produce section of your store.  Just use one tablespoon or  two medium sized lobes of garlic, more is not better here.  Also, about a cup of chopped celery and a cup of mild peppers (bell peppers, red preferably to add red color, since there will not be any tomatoes in this soup, but some Poblanos or Anaheims will add a little more kick to the Gumbo).  Fresh Chopped Parsley is another ingredient that is optional, but traditional (or you may substitute "Chinese Parsley," currently known popularly as "Cilantro" or Celentro," depending on how you want to spell it).
  6)  Beans!  County-style Gumbo usually has green lima beans, but I prefer French-cut green beans.  One can per gallon of Gumbo.  As with all these canned products, pour the juice in the stock pot with the beans.
  7)  Season to taste!  The basics are salt and pepper (for this base, use white pepper if you have it), one bay leaf per gallon of Gumbo, a tablespoon of thyme--or less for blander gumbo, a teaspoon of tarragon, and a dash of rosemary.  I like a few (2-3) bulbs of shallots with the onion/garlic.
  8)  Roux.  Roux is the traditional ingredient for thickening sauces, soups, stews, etc.  Here is where we part ways.  In traditional Cajun Cookin', they don't make the roux separately, they cook the vegetables in with it!  The trouble I have with this method is that I cannot predict before the gumbo is made, how much thickener I will want to add, to get the Gumbo just right.  
For the traditional method, put about one half cup of butter/oleo/blend in a skillet, heat until melted.  Add a cup of All Purpose Flour, mixing until all the flour is  suspended in the oil.  Cook over low heat until the roux turns into a medium brown, but do not allow it to burn!  This means the flour is cooked.
For the Cajun method, put olive or peanut oil in the skillet, add the vegetables and the flour all together.  Cook until the roux has thickened and turned brown.  This will all be added at the same time, in the step titled "Carelessly, throw in the rest of the ingredients" below.
Be sure to get it thoroughly cooked, so that the Gumbo doesn't taste like
flour.  
Cornstarch can be used, or even taro root, to thicken the stock.
Add a little at a time.  Don't over-thicken, as this will "set up" a little
after it is allowed to "rest" for an hour.
 
--In the stock pot, put about a quart of water and simmer the chicken breasts and seasonings.  Let them cook for a while, about an hour, until tender, and "pull" the chicken into pieces.
--In a pan, put one tablespoon of oil (any will do, peanut or olive will give the best flavor), and get it hot before adding the:  diced onions, shallots, garlic, and peppers.  Sautee until "clarified," do not caramelize.  Dump this in with the chicken.
--Carelessly, throw in the rest of the ingredients, except for the roux or the thickener.  Never be too careful, slop a little on the counter and the edge of the pot, so that they know that you love them, too.  
--Simmer for an hour, to allow the flavors to migrate.  Pent up flavors are unhappy flavors, and they might cause you to get heartburn, just out of spite.  Like a jealous puppy, this Gumbo wants love, and it will act up if it doesn't get the attention due it.  Oh, and add water if it gets too thick.  
--Here is where I take my fork of the road.  I like to add a good saltwater white-fleshed fish.  Snapper or grouper is best, but Atlantic pollock, bluefish, or other similar fish is good.  No freshwater fish allowed, they know who they are!  No whiting, rockfish, so-called "Pacific pollock" or wimpy fish like flatfish (sole, flounder, halibut).  8 Oz is good, a pound is better, "...and it has made all the difference."
--Thicken the Gumbo.  Add the roux a tablespoon at a time, stir for a minute between portions, then add more as needed.  I like the gumbo to have some body, "...everybody needs somebody sometime!"
--If you can stand it, let the Gumbo "rest" away from the heat for an hour.  Cover (to prevent bacteria from migrating in from the air) and leave on the stove.
--Traditionally, Gumbo is served on a bed of rice.  Use Louisiana rice, long-grain polished white rice, the plain old rice, but never use converted or "parboiled rice" (there ought to be a law!!!!).
--Don't choke on the bay leaf.  Contrary to urban myths, bay leaves are not poisonous, choking is.
--Eat until you feel like you will burst, wait two hours, and then eat even more than you did the first time.
--The next day, the Gumbo is even better, after it has had a chance to contemplate who it is, where it came from, why is it here, and "...what is the meaning of Gumbo?".
 Hope this works for you.  If it doesn't, that doesn't mean it's my fault, since I clearly said "season to taste" earlier in the recipe.  Remember, all good cooking is intuitive, so use what you feel like using, and leave out what you don't like,
except for the okra!
~Mark A. Rector
Lazy R Ranch Miniature Horses