Heat the vegetable oil in a large pot over medium heat.

Gradually whisk in the flour and stir continuously until the roux turns a deep brown color, about 15-20 minutes.

Once the roux is ready, add the diced onion, bell pepper, and celery. Cook for about 5 minutes until the vegetables soften.

Stir in the minced garlic, Cajun seasoning, and thyme. Cook for another 1-2 minutes to release the flavors.

Add the chicken pieces and sausage to the pot, stirring to coat with the roux. Cook for about 5 minutes until the chicken is lightly browned.

Carefully pour in the chicken broth, scraping the bottom of the pot to incorporate any browned bits.

Add the sliced okra and bay leaves. Bring the mixture to a boil, then reduce the heat and let it simmer for at least 1 hour, stirring occasionally.

After simmering, taste the gumbo and adjust seasoning with salt and pepper if necessary. Remove the bay leaves before serving.

Serve the gumbo hot over a scoop of cooked rice and garnish with chopped green onions.