Sausage and Chicken Gumbo

Name: Sausage and Chicken Gumbo
Ingredients: 3 tablespoons plus 3/4 cup vegetable oil; 2.5 pounds bone-in chicken breasts; Kosher salt and freshly ground black pepper; 1 cup flour; 4 stalks celery, thinly sliced; 4 large onions, diced; 4 bell peppers, diced (I used 2 green and 2 red); 2 tablespoons minced garlic; 1/2 to 1 teaspoon cayenne pepper; 3/4 teaspoon oregano; 3/4 teaspoon basil; 3/4 teaspoon thyme; 4 bay leaves; 8 cups chicken broth, good quality canned or homemade; 1.5 pounds andouille sausage cut into slices, then quartered; 1 tablespoon filé powder or gumbo seasoning with filé powder; 4 cups cooked white rice