Heat the ½ cup vegetable oil in a large Dutch oven or heavy-bottomed pot over medium heat. Once shimmering, whisk in the ½ cup all-purpose flour until smooth. Switch to a wooden spoon or heat-safe spatula.

Cook the roux, stirring constantly and scraping the bottom of the pot, for 25–35 minutes. You're aiming for a deep chocolate-brown color — like dark milk chocolate or a copper penny. Don't rush this step and don't walk away. If it smells burnt, reduce the heat.

Once the roux is dark and fragrant, immediately add the diced yellow onion diced, 1 green bell pepper diced, and 3 stalks celery diced. The vegetables will sizzle dramatically — this is normal. Stir vigorously to coat everything in the roux and stop the cooking. Cook, stirring frequently, for 6–8 minutes until the vegetables soften.

Add the minced cloves garlic minced and cook for 1 more minute, stirring constantly, until fragrant.

Add the sliced andouille sausage sliced into ¼-inch rounds to the pot and stir to combine. Cook for 3–4 minutes to lightly brown the sausage and render some of its fat into the base.

Add the 1 ½ lb boneless skinless chicken thighs cut into 1-inch pieces, all of the spice blend ingredients (2 tsp Cajun seasoning, 1 tsp smoked paprika, 1 tsp dried thyme, 1 tsp dried oregano, ½ tsp black pepper, ¼ tsp cayenne pepper add more, 2 tsp kosher salt, 2 tsp Worcestershire sauce, and 2 pieces bay leaves), and stir well to coat everything evenly.

Pour in the 6 cups chicken broth low-sodium preferred and add the 1 can diced tomatoes with their juices. Stir well, scraping up any bits from the bottom of the pot. Bring to a boil over high heat, then reduce to a gentle simmer.

Simmer uncovered for 40–45 minutes, stirring occasionally, until the 1 ½ lb boneless skinless chicken thighs cut into 1-inch pieces are very tender and the gumbo has thickened and deepened in flavor. Skim any excess fat or foam from the surface as needed.

Stir in the 1 ½ cups frozen okra sliced and cook for 10 minutes. The 1 ½ cups frozen okra sliced adds both flavor and natural thickening to the gumbo.

Use fully peeled and deveined shrimp. If frozen, thaw overnight in the refrigerator — never cook from frozen in a skillet or released water will kill the sear. Pat shrimp completely dry with paper towels. Season with salt just before cooking; add paprika, garlic salt, or red pepper flakes if using. Have lemon, parsley, and butter measured and ready before the shrimp hit the pan — cook time is short.

Heat a large skillet over medium to medium-high heat. Add enough olive oil, butter, or both to coat the pan. For garlic or red pepper flakes, add to the oil first and sauté 1–2 minutes until fragrant — don't let the garlic burn. Once the fat is hot and shimmering, add shrimp in a single layer. Don't crowd the pan or they'll steam instead of sauté — work in batches if needed. Cook without moving for 1.5–2 minutes per side, flipping once. Total time: 2–3 minutes for small shrimp, 4–5 minutes for large. Watch closely — they overcook fast. Optional: add a splash of wine, lemon juice, or broth once shrimp are nearly done. Let reduce about 1 minute. Finish with a squeeze of fresh lemon.