1 cup vegetable oil
1 cup flour
3 onions, chopped
2 ribs celery, finely chopped
1 large green bell pepper, roughly chopped
1 large red bell pepper, roughly chopped
2 tablespoons minced garlic
8 cups chicken stock, warmed
1/2 teaspoon cayenne, plus more to taste
2 bay leaves
4 sprigs fresh thyme
1 1/2 pounds Andouille sausage, cut into 1-inch pieces
Salt to taste
3 1/2 cups boiled chicken, bones discarded and meat left in large chunks
1 pound cut okra
3 cups chopped and seeded tomatoes
1 bunch scallions, thinly sliced
Cooked white rice, for serving
Hot sauce, for serving
In a large, heavy-bottomed Dutch oven, heat oil over medium-high heat; whisk in flour. Cook, stirring constantly, reaching every portion of the bottom of the pot, until roux begins to take on some color. Reduce heat to medium or medium-low and continue cooking and stirring constantly until roux reaches the color of milk chocolate.
Add the onions, celery, bell peppers and garlic, and cook, stirring frequently, until vegetables have softened, 5 to 7 minutes. Whisk in the chicken stock, cayenne, bay leaves and thyme and bring to a gentle simmer. Continue to simmer until sauce is thickened and flavorful, about 2 hours, skimming any foam or excess oil that comes to the surface. While simmering, saute sausage in a large skillet over medium-high heat until browned on all sides. Add sausage to gumbo. Taste gumbo and season lightly with salt, if needed. Simmer for 2 additional hours.
After simmering, remove bay leaves and thyme sprigs and add chicken, okra, tomatoes, and chopped scallions to gumbo. Stir well and continue to simmer for 30 minutes longer. Adjust thickness if necessary, then adjust seasoning with salt, to taste.
Serve gumbo ladled over hot white rice in large bowl