Here's my gumbo recipe, this one was duck and venison sausage but you can sub any meat. I've never used store bought roux so can't comment on that, but I use peanut oil and flour for mine. IMO the most overlooked part of gumbo is having a good stock. If using duck, dove, chicken venison etc. save the carcass/bones and put in the oven at 500 with carrot onion celery until brown. Throw it all in a stock pot and fill with water and let simmer for a few hours. Strain everything out and set aside.
I like a dark roux for meat based gumbo. Pull it off heat just before it gets the color you want, it will continue to darken as it sits.
You can see how much darker it gets.
Rough chop onion, celery, bell pepper and garlic, lots of garlic. I take all the veggies and saute in pot with olive oil until hot, then put in as much roux as you think you need. Stir it all together and make sure it's hot and then start adding stock about a cup at a time. Make sure it incorporates before you add another cup so it doesn't clump together.
Time to season. Right above the stock picture above is my seasoning. I like fresh thyme, dried parsley, salt, pepper, paprika & cayenne. 2 bay leaves also. Put all your seasoning in and your meat, except sausage if you're using it. Let simmer for at least 1 hour, longer the better IMO. Use a ladle to get any oil that rises to top. Adjust seasoning if needed. I add sausage 20 mins or so before serving.
Rice or bread, some green onion, tabasco and a cold one.