Place a heavy-bottomed pot or Dutch oven over medium-low heat. Add vegetable oil and warm for 1 minute. Whisk in the flour constantly to combine. Keep stirring frequently with a wooden spoon or spatula, scraping the bottom and sides, until the roux turns the color of milk chocolate to a dark chocolate (a deep brown) — about 25 to 35 minutes. Reduce heat as needed to prevent burning. The roux is the flavor base; patience is required.

When the roux reaches desired color and has a nutty aroma, reduce heat to medium-low and add the diced onion, green bell pepper, and celery (the 'Holy Trinity'). Stir and cook in the roux for 6–8 minutes until vegetables soften and begin to caramelize. Add the minced garlic and cook 30–60 seconds until fragrant.

Stock and Seasoning

Add the sliced andouille sausage to the pot and stir for 2–3 minutes to brown slightly and release fat into the roux-vegetable mixture.

Slowly whisk in about 1 cup of the chicken stock to deglaze the pot and loosen browned bits, mixing thoroughly so the roux incorporates into the liquid without lumps. Then gradually whisk in the remaining 7 cups of stock until smooth.

Add the chicken pieces, crushed tomatoes, bay leaves, dried thyme, smoked paprika, cayenne, salt, and black pepper. Stir to combine. Bring the gumbo to a gentle simmer, then reduce heat so it maintains a low simmer. Partially cover and simmer for 35–45 minutes, stirring occasionally. During this time the chicken will cook through and flavors will meld.

Taste and adjust seasoning, adding up to 0.5 tsp more salt or a pinch more cayenne if you prefer more heat. Remove and discard bay leaves.

Thickening, Seafood Finish & Serving

If using shrimp, stir them into the simmering gumbo in the last 4–6 minutes of cooking until pink and opaque. Do not overcook shrimp. If you prefer to brown the chicken first for more flavor, sear pieces in a separate skillet before adding to the gumbo earlier in the simmer step.

If the gumbo seems thin, simmer uncovered for 5–10 additional minutes to reduce and thicken, stirring to prevent sticking. Optionally sprinkle the file powder into the gumbo at the very end (1 tsp), stir and remove from heat — file thickens and adds a distinct flavor; do not boil after adding file.

Ladle gumbo over bowls of hot cooked white rice. Garnish with sliced green onions and chopped parsley. Serve immediately with extra hot sauce at the table if desired.