Step 1: Make the Roux

1. Heat Oil:
   • In a large pot or Dutch oven, heat the vegetable oil over medium heat.
2. Whisk the Flour:
   • Gradually whisk in the flour to form a roux. Stir continuously to prevent burning. Cook the roux until it turns a deep, rich brown color, about 15-20 minutes.

Step 2: Cook the Vegetables

1. Add the Holy Trinity:
   • Stir in the diced onion, bell pepper, and celery. Cook for about 5 minutes, stirring occasionally, until the vegetables are softened.
2. Add Garlic:
   • Stir in the minced garlic and cook for another minute until fragrant.

Step 3: Cook the Chicken and Sausage

1. Brown the Proteins:
   • Add the chicken pieces and sliced turkey sausage to the pot. Cook for about 5 minutes, stirring occasionally, until the chicken is lightly browned.

Step 4: Simmer the Gumbo

1. Add Liquids and Seasoning:
   • Pour in the chicken broth and add the can of diced tomatoes (with juices). Stir well to combine.
2. Season:
   • Add Cajun seasoning, dried thyme, and the bay leaf. Season with salt and pepper to taste.
3. Simmer:
   • Bring the gumbo to a boil, then reduce the heat to low. Let it simmer gently for 30-40 minutes, stirring occasionally, to allow the flavors to meld and the sauce to thicken.

Step 5: Serve

1. Remove Bay Leaf:
   • Before serving, discard the bay leaf from the gumbo.
2. Plate the Dish:
   • Spoon the gumbo over a bed of cooked white rice.
3. Garnish:
   • Sprinkle with chopped green onions and parsley for a fresh, vibrant finish.