Chicken and Andouille Sausage Gumbo

Name: Chicken and Andouille Sausage Gumbo
Ingredients: Cajun Seasoning; 1 tablespoon Cayenne Pepper; 1 teaspoon Ground Black Pepper; 1 tablespoon Dried Oregano; 1 tablespoon Paprika; 2 1/2 teaspoons Salt; Main Ingredients; 1/2 cup Oil (I use olive, but peanut oil works best); 1/2 cup Flour; 1 Yellow Onion- coarsely chopped; 2 Large Carrots- coarsely chopped; 3 Celery Stalks- coarsely chopped; 2 Cloves of Garlic; 2 teaspoons Cajun Seasoning (recipe above); 64 ounces Chicken broth (I usually just put enough to fill my Le Creuset Dutch Oven 3/4 of the way full); 1 pound Andouille Sausage- cut into 1/4 inch thick slices; 1.5 pounds Skinless Boneless Chicken Thighs (you can use breast if you prefer, I just love the rich flavor the thighs offer the soup); 2 cups Rice (I use brown basmati); 1 pinch File Powder (if desired)