Make the Roux: In a large, heavy-bottomed pot, melt 3 tablespoons of butter over medium heat. Add 3 tablespoons of flour and stir continuously to make a roux. Cook, stirring frequently, until the roux turns a deep brown color, almost like chocolate, about 15-20 minutes. Be patient and keep stirring to avoid burning.Once the roux reaches the desired color, incorporate the remaining 3 tablespoons of flour mixed with a bit of stock. This will help achieve the desired texture. Continue stirring until well combined. Add Vegetables: Once the roux is ready, add the chopped onion, green onions, and red bell pepper. Sauté until the vegetables are soft, about 5 minutes.
Incorporate Okra and Tomato Paste: Add the sliced okra and tomato paste to the pot. Stir well to combine and cook for another 5 minutes, allowing the tomato paste to caramelize slightly.
Season and Add Stock: Sprinkle in the oregano, salt, black pepper, and cayenne pepper (if using). Pour in the fish stock and add the bay leaves. Stir everything together, scraping the bottom of the pot to release any browned bits.
Simmer: Bring the mixture to a simmer. Reduce the heat to low and let it cook for about 30 minutes, stirring occasionally to ensure nothing sticks to the bottom.
Cook the Sausage: In a separate skillet, brown the sliced turkey sausage over medium heat for about 5 minutes. This step adds flavor and helps reduce excess fat.
Combine Sausage and Shrimp: Add the browned sausage to the pot. Continue to simmer for another 10 minutes. Finally, add the shrimp and cook until they are pink and opaque, about 5 minutes.
Adjust Seasoning and Serve: Taste the gumbo and adjust the seasoning with more salt and pepper if necessary. Remove the bay leaves before serving.