In a cast iron Dutch oven, heat 1/2 cup of the oil over medium heat. Season the chicken with salt, pepper, cayenne and red pepper flakes. Brown tasso and sausage and set aside. Next, add chicken and sear. When chicken is golden brown, add the rest of the oil and the flour, on medium heat, and stir constantly until a dark roux starts to form.
Once dark roux has formed, stir in tomato paste, onions, celery, garlic and bell peppers. Stir on a low heat for 10 minutes until the sauce starts to turn brown.
Once sauce is brown, stir in the chicken, tasso and andouille sausage. Stir for an additional 10-15 minutes until sauce has completely coated the meat evenly.
Stir in the chicken broth a little at a time, while constantly stirring. Once all of the chicken broth is in, bring mixture to a slow simmer for about 30-45 minutes or until chicken is tender. Taste and season. Add chopped green onions before serving over white rice.