Preheat oven to 400 degrees F. Heat 1 tablespoon oil in a small skillet, add half of chopped vegetable mirepoix and saute 2 to 3 minutes until softened; season to taste with salt and pepper. Add chorizo and leeks and cook 2 minutes. Add shrimp, toss to mix and season with Creole spice and thyme. Add bread crumbs and cook a few moments more, just until mixture is heated through. Transfer to a bowl to cool. Taste and adjust seasoning.
Open a pocket in top of fish by cutting down one side of the backbone. Pocket should be about 6 inches wide. Season pocket and stomach cavity generously with salt, pepper and Creole spice; transfer fish to a baking sheet. Stuff half of stuffing into pocket and remainder into cavity. Brush entire fish with olive oil.
Make a salsa: combine tomatoes with remaining cup of chopped vegetable mirepoix and about 1 1/2 tablespoons oil; season with Creole spice. Spoon salsa over entire fish. Roast 20 minutes, until just cooked through. To serve, transfer fish to a large platter and drizzle with extra-virgin olive oil. Remove fish from bone at table.
Yield: 3 to 4 servings