Shrimp and Crab Gumbo

Name: Shrimp and Crab Gumbo
Ingredients: * 1/2 cup vegetable oil; * 1/2 cup flour; * 1 medium onion, diced; * 1 green pepper, diced; * 5-6 clove garlic, minced; * 1 pound okra (fresh or frozen),; * 1 16-ounce can tomato sauce; * 1 16-ounce can diced tomato; * 1 1/2 teaspoon dried thyme; * 1 1/2 quart seafood stock or chicken stock; * 1/3 cup worcestershire sauce; * 2 bay leaf; * 1 1/2 teaspoon salt; * 1/2 teaspoon black pepper; * 1 pound raw shrimp, peeled and deveined; * 1 pound cooked lump crab meat; * 1 tablespoon file powder