Heat ¼ cup of the oil in a 4-quart pot over medium-high heat. Add the bell peppers and onions and cook until lightly golden and softened, about 6 minutes. Add the garlic and crushed red pepper and cook, stirring, until fragrant, 1 to 2 minutes longer. Add the wine and cook until reduced by half. Add the shrimp stock and bring to a simmer. Add the tomatoes, olives, caper juice, 4 of the thyme sprigs, oregano and basil sprigs, season lightly with salt and pepper, and add the crabs. Bring to a boil; reduce heat, and simmer until the tomatoes have broken down and the sauce is thick and flavorful, 45 minutes to an hour. Stir in the Pernod, remove the herb sprigs, and set the sauce aside while you assemble the seafood pouches. 

Preheat a grill to high heat.

Cut 6 pieces of heavy duty aluminum foil about 18 inches square. Top each piece of foil with a piece of parchment paper roughly the same size. If you are working alone, place one foil and parchment stack into the bottom of a shallow mixing bowl, parchment side up, bringing the edges of the foil upward to form a bowl shape. Assemble all of your raw seafood on a baking sheet, drizzle with some of the remaining olive oil, and season the seafood on all sides with Creole Seasoning. Place one portion of snapper, 2 of the shrimp, 1 ½ ounces of the calamari, and 3 clams in the center of each foil “bowl”. Ladle about ¾ cup of the sauce over each seafood stack. Top each with one of the crab halves, a sprig of thyme, and a drizzle of the remaining olive oil. Bring the edges of the foil up together and either twist to close tightly or bring edges together and roll the edges tightly to close, so that you have airtight pouches. (Note:  the parchment must not be visible above the upper edges of the pouches, or it will burn on the grill.)

Carefully position the pouches on the grill, taking care not to puncture the foil. Close the lid of the grill and cook until the seafood inside is just cooked through, usually 10 to 12 minutes. Remove the pouches from the grill and place in shallow bowls for guests to open at the table. Garnish each pouch with some of the Calabrian chile slices and some of the basil chiffonade; serve with sourdough bread and lemon wedges.