Make the Roux: Set a large 7-8 quart saucepot over medium-high heat. Add the flour, oil, and butter. Whisk well to break up any clumps. Cook the roux for 30-40 minutes, whisking regularly, until it is the color of milk chocolate.

Prep: Meanwhile, chop the sausages, all the vegetables, and herbs.

De-Slime the Okra: Set a smaller saucepot filled with water and over high heat. Add the vinegar. Once boiling, add the chopped okra. Boil for 3-4 minutes to reduce the slime. Then drain and set aside.

Build the Base: Once the roux is a dark rich brown color, add in the andouille sausages. Fry it in the roux for 1-2 minutes, then add in the chopped onion, bell pepper, celery, garlic, and habanero. Stir and sauté for 8-10 minutes.

Slow Simmer: Add in the seafood broth, Worcestershire sauce, thyme, Cajun seasoning, bay leaf. Stir well. Then mix in the crawfish and whole crabs. Simmer on low for 1 hour.

Cook the Rice: Use the same smaller pot you used for the okra to cook the rice. Cook according to the package instructions. Once cooked, fluff the rice, and cover until ready to use.

Finish: Now add the shrimp, oysters (plus crabmeat if using), and okra. Simmer another 5 minutes.

Rest: Cover the gumbo pot and turn off the heat. Let the gumbo rest for at least 30 minutes, so all the flavors have longer to mix and mingle, without overcooking the seafood.

To Serve: Rewarm the gumbo, if needed, for 2-3 minutes. Then serve it in large bowls with a heaping scoop of rice, and a sprinkling of parsley and/or scallions.