This gorgeous dish of layered shellfish and seafood is based on a recipe that sommelier Richard Betts found in a 1995 issue of F&W. He still has the original cooking-stained recipe, though the pot he makes it in is even older: a Dutch oven that's been in the Betts family since 1839. "It's pretty wild," he says. "Civil War meals were cooked in that pot!" Betts freely adapts the recipe to whatever looks best at the market, but he always follows the same formula: fish on the bottom, shellfish on the top. "It's so impressive," he says. "When you pull it out of the oven, people freak."

Ingredients

• 1/4 cup extra-virgin olive oil, plus more for serving
• 1 large sweet onion, thinly sliced
• 2 garlic cloves, thinly sliced
• 1/4 cup finely chopped flat-leaf parsley
• 1/2 teaspoon crushed red pepper
• 1 28-ounce can whole peeled Italian tomatoes, drained and chopped
• 2 strips of orange zest, optional
• Salt and freshly ground black pepper
• 4 8-ounce skinless halibut or other meaty white fish fillets
• 2 cups pitted green and black olives, such as picholine and kalamata (about 3/4 pound)
• 2 pounds large shrimp, shelled and deveined
• 1 pound cleaned calamari, bodies cut into 1/2-inch rings
• 20 littleneck clams, scrubbed
• 1 pound mussels, scrubbed and debearded
• 2 cups bottled clam juice
• 1 cup dry white wine
• Grilled bread, for serving; optional

Directions

• Preheat the oven to 450 degrees. In a large, enameled cast-iron casserole, heat the 1/4 cup of olive oil. Add the onion and garlic, cover partially and cook over low heat, stirring occasionally, until softened, about 8 minutes. Add the parsley and crushed red pepper and cook over moderate heat, stirring, for 1 minute. Add the tomatoes and cook until almost all of the liquid has evaporated, about 5 minutes. Add the orange zest, season with salt and black pepper, and remove from the heat.
• Arrange the halibut fillets in the casserole and season with salt and pepper. Scatter the olives over the fish and top with the shrimp and calamari. Season lightly with salt and pepper. Tuck in the clams and mussels, hinge sides down.
• In a medium saucepan, bring the clam juice and white wine to a boil. Pour the hot liquid over the seafood. Cover and bake for about 30 minutes, or until the mussels and clams open, the shrimp are pink, the calamari is opaque and the halibut is cooked through. Transfer any unopened clams and mussels to the saucepan and add 1 cup of the cooking liquid from the casserole. Cover and simmer until they open, about 3 minutes; discard any that don't open.
• Spoon the seafood and broth into bowls and serve right away, passing grilled bread and additional olive oil at the table.