I had an old cajun friend that made homemade gumbo the right way with fresh seafood right off the boat from NOLA.  He would take one day to chop up the vegetables using fresh out of the garden onions, peppers and oakra.  He worked on a tow boat that went from Cairo IL to NOLA and back.  He would pick up the seafood in NOLA right off the seafood dock and keep it on ice then bring it back home by car when he got off work for a few weeks.  He made the roux from scratch.  It took two days but it was good.
 
My question is this.  I have never made a roux and I could probably do it fine but I started using a Zatarain’s gumbo mix.  I add to the recipe by boiling the recommended amount of water with a can of whole tomatoes, chopped onion, celery, garlic and peppers.  I add the mix easily stirring as I add it as it will stick.  After a couple of hours I add the seafood which is usually from Kroger’s and not the seafood dock at NOLA.  I add oakra along that time which comes from Kroger too but it’s good gumbo.  I make it thich like a stew but my wife always adds tomato sauce to thin it up some. 
 
Also I hardly every make gumbo except in the winter.  It’s something about wanting a bowl of hot soup in the winter but not in the summer when it’s so very hot. 
 
Thanks for your response.  Good old Zatarain.  Oh and I get the kind with no rice in it.  Actually we cook rice on the side for our guests but usually don’t add it for outselves.  We like it right out of the pot.