Gumbo came to the United States through West Africa, as part of the Atlantic slave trade. In fact, gumbo is a traditional African word for "okra." As the dish traveled through the South, it was influenced by each region. There's Creole gumbo, which is roux-based, and Cajun-style gumbo, which is made with tomatoes. This version is Creole, but try different kinds so you can see just how diverse the dish can be.
Prepare the vegetables. Remove sausage from the casings and crumble. Set aside.
Season the diced chicken with 3–4 tablespoons of Creole Spice Mix, either homemade or a high-quality store-bought mix. Dredge the chicken in ½ cup all-purpose flour.
In a large pot over medium-high heat, heat ½ cup of lard. When melted, add the andouille and slightly flatten to an even layer; brown on both sides, just cooking through. (Do not overstir, or meat will not sear.) Remove from the pan with a slotted spoon so oil remains in pan, and drain on a paper towel-lined plate. Set aside.Add the chicken to the hot pan. Allow the chicken to brown and cook through in two batches, being careful not to overstir, about 7 minutes. Remove from the pan and set aside with the sausage.
Roux: Turn the heat to low. Scrape food bits from the bottom of pan (also known as "fond") so they are loose in the melted fat. Add the remaining ½ cup lard and allow it to melt. Dust in the remaining ¾ cup flour in several small additions, whisking constantly. Simmer on low heat, stirring constantly with a wooden spoon so roux does not stick, for 30–45 minutes, until the roux is the color of peanut butter.
Raise the heat slightly. When the roux has just begun to bubble, add the onions and stir well to coat them. Then add the celery and bell pepper and cook for 5 minutes, stirring, to just soften. (The goal is to "stew," not sear.) Add the garlic. Slowly add the stock in several additions, stirring and scraping constantly to deglaze and mix well. Bring to a simmer over medium-high heat. Add the bay leaves and the filé, and stir. Simmer for 20–30 minutes, until "nappe consistency"—thick enough to coat the back of a spoon.
Add the chicken and sausage pieces and simmer.
Heat a dry cast-iron skillet. Toss okra lightly in oil, then grill in the hot pan, stirring occasionally, until seared and aromatic. Remove, cool slightly, and chop into ½-inch pieces. Add to the pot and stir.
Adjust seasoning to taste with salt and pepper. Season with hot sauce, lemon, and some of the spice mix to taste. Serve with rice.
Creole Spice Mix
Combine all the ingredients for the Creole Spice Mix in a bowl and mix well to combine. Set aside.