Preparation time: 4 hours
Cooking time: Same
It's all below. Be innovative.
You need oil and flour to make a roux. I usually use 1/2 olive oil and 1/2 veggie oil. Over medium heat, start with half a cup of oil (and this HAS to be in a cast iron skillet - no way around it), get it hot enough so that when you drop water in it it sizzles. Put flour in a couple spoonfuls at a time until you've done a half cup. You'll probably want to add more flour as you go. The roux needs to become a dark brown - like chocolate - so this'll take about an hour. Fortunately, during this time you also get to brown a can of tomato paste and about 3 Roma tomatoes in butter. You can also chop up a cup of celery and a cup of white onion, and maybe press some garlic. See, no boredom here! But remember to keep stirring the roux. The tomato stuff is done when it loses the bright red color. And stir the roux some more.
After you've got your roux the right color, you can add the celery and onions and garlic and saute for 30-40 minutes. This is usually when I'll add a couple more tablespoons of oil. Also toss in the tomato stuff. When the time's up, transfer all of this to a ginormous pot. I'm talking several gallons here. Add water. I usually start with 6 cups or so and add more at the end if it's way too thick. Simmer all this together for an hour.
After the hour's up, make the gumbo your own. I usually do canned crabmeat (6 cans or so - drain it well!), crawfish tails if I can find them, and I like clams too. Also, shrimp shrimp shrimp, but add these at the very end, since overcooked shrimp blows.
Season to taste, whatever that means. I use Tony Chachere's, Old Bay, cayenne, Cholula (not authentic but SO much better than vinegary Tabasco), salt, pepper, oregano, whatever...
You can serve this over rice, but with the crabmeat you really don't need to.
Good luck! Lots of work but way rewarding