Seafood File Gumbo

Name: Seafood File Gumbo
Ingredients: 1/4 cup butter; 1/4 cup all purpose flour; 1 onion, chopped; 2 cloves garlic, crushed; 1/2 green pepper, chopped; 1/2 sweet red pepper, chopped; 1/2 teaspoon thyme; 5 cups Spicy Shrimp Stock (recipe follows); 1 (14 ½ oz.) can whole tomatoes, drained; 1 bay leaf; Dash Worcestershire sauce; 2 - 3 dashes Louisiana hot sauce; Salt, to taste; 1 pound fresh lump crabmeat; 2 lbs. raw shrimp, peeled and deveined (reserve shells); 1 cup shucked raw oysters, with liquid; 2 tablespoons fresh parsley, chopped; 2 tablespoons file powder; Steamed rice, for serving