Authentic Cajun Gumbo

Ingredients

• 6 quarts water
• 1 chicken (5 pounds), cut up
• 2 large onions, quartered
• 4 celery ribs, cut into 3-inch pieces
• 6 garlic cloves, coarsely chopped
• 2 tablespoons salt
• 1 teaspoon garlic powder
• 1/2 teaspoon poultry seasoning
• 1/2 teaspoon cayenne pepper
• 1/2 teaspoon pepper
• 1/4 teaspoon white pepper
• 1 cup canola oil
• 1-1/2 cups all-purpose flour
• 1 large onion, finely chopped
• 1 pound fully cooked andouille sausage links, chopped
• 2 pounds sliced okra
• 2 pints shucked oysters
• 3 tablespoons gumbo file powder
• Hot cooked rice