1Pat the chicken dry and toss with 1 tsp of the Cajun seasoning, a pinch of salt and a few grinds of pepper.
2Heat 1 tbsp vegetable oil in a dutch oven over medium-high heat. Brown the andouille coins for about 4 minutes until the edges crisp, then move to a plate. Brown the chicken in the same pot in a single layer, working in batches, about 2 minutes per side. It does not need to cook through. Move it to the plate with the sausage.
3Wipe out any burnt bits from the pot but leave the browned film on the bottom. Lower the heat to medium-low, add 1/2 cup vegetable oil and whisk in the flour until smooth.
4Make the roux: stir constantly with a flat-edged wooden spoon or a whisk, scraping the corners, for 35 to 45 minutes. It will go from blond to peanut butter to copper to the color of dark chocolate. If you see black flecks or smell anything acrid, it has burned; throw it out and start over.
5The moment the roux hits dark chocolate, stir in the onion, celery and green bell pepper. The roux will sizzle and seize up and the vegetables will stop it from cooking further. Stir for 5 minutes until the vegetables soften, then add the garlic and cook for 1 minute.
6Add the warm broth about 1 cup at a time, whisking well after each addition so the roux dissolves without lumps. Stir in the bay leaves, thyme, remaining Cajun seasoning, cayenne and Worcestershire sauce.
7Return the chicken and andouille, plus any juices on the plate, to the pot. Bring to a gentle boil, then reduce the heat to low and simmer partially covered for 1 hour 15 minutes, stirring now and then. Skim the reddish oil off the surface with a spoon as it rises.
8Stir in the okra, if using, and simmer 20 minutes more until the chicken is fork-tender and the gumbo coats the back of a spoon. Meanwhile, cook the rice according to the package directions.
9Fish out the bay leaves. Taste and adjust with salt, pepper and more cayenne. Ladle over mounds of rice and top with green onions and parsley. Pass hot sauce at the table.