Season the chicken on both sides with kosher salt and pepper.
Heat 2 tablespoons of the oil in a large Dutch oven or heavy-duty pot over medium heat. When the oil is hot, add the chicken and cook for 4-5 minutes, undisturbed until light golden brown. Flip to the other side and repeat cooking for another 5 minutes.
When chicken is browned on both sides, remove it to a plate and set aside. Add the sliced sausage to the pan and cook, stirring occasionally for 3-4 minutes or beginning to brown. Remove sausage with a slotted spoon to the bowl with the chicken.
Reduce heat to medium-low and add the rest of the oil to the pot. With a metal spatula or wooden spoon scrape off the brown bits on the bottom of the pan. (These will add great flavor to your roux.)
Add the flour, ¼ cup at a time, stirring constantly after each addition, until all lumps have disappeared.
Continue to cook on medium-low, maintaining a low but steady simmer. Stir every 3-4 minutes (more frequently during the last 5-8 minutes) until the mixture reaches a deep golden brown color. This will take about 30-35 minutes, depending on your heat level. If the roux starts changing too color quickly, reduce the heat so it won’t burn.
Add the carrots, bell pepper, onion, and celery and cook 2-3 minutes, stirring frequently. Add the garlic, cook and stir for another 30 seconds.
Slowly add the chicken broth while stirring. Add the reserved chicken, sausage, bay leaves, paprika, oregano, onion powder, garlic powder, cayenne and pepper.
Drain the fire-roasted tomatoes through a sieve. Add the drained liquid to the pot. With your fingers break up the tomatoes into smaller bits then add the tomatoes to the pot.
Simmer for 45 minutes, stirring occasionally. Remove the chicken with a slotted spoon to a plate and allow to cool. When cool, pull the chicken apart into bite-size pieces and return to the pot. Serve warm on its own or with jasmine or basmati rice.