Seafood Linguine

Heat wine in a large Dutch oven over medium-high until simmering. Add cockles and mussels, cover pot, and cook until shellfish have opened, about 5 minutes. (Discard any unopened ones.) Using a slotted spoon, remove shellfish and transfer to a bowl. Shuck half of mussels; discard shells. Cover shellfish with foil to keep warm. Strain liquid through a fine-mesh sieve. (You should have about 1 cup broth.)

Wipe Dutch oven clean with a paper towel. Heat 2 tablespoons oil over medium-high, swirling to coat bottom. Pat scallops dry with a paper towel; season with salt and pepper. Add to Dutch oven and cook, flipping once, until golden brown and cooked through, about 3 minutes per side. Transfer to a plate; loosely cover with foil.

Add remaining 2 tablespoons oil to pan drippings in Dutch oven; reduce heat to medium. Add onion and garlic and cook, stirring occasionally, until softened, 6 to 8 minutes. Add red-pepper flakes and tomato paste and cook, stirring, 1 to 2 minutes. Add shellfish broth and cook, scraping up browned bits with a wooden spoon, until mixture is reduced by half, about 2 minutes. Add tomatoes with their juices and simmer, stirring occasionally, until slightly thickened, about 15 minutes. Season with salt and pepper. Add shrimp and squid and cook, stirring occasionally, until just cooked through and shrimp are bright pink, about 2 minutes.

Meanwhile, cook pasta according to package instructions in a large pot of generously salted water. Drain, reserving 1 cup pasta water. Toss pasta with tomato sauce, adding pasta water to adjust consistency until creamy. Gently stir in cockles and mussels, reserving a few for garnish if desired. Transfer to a large serving platter; top with scallops and reserved shellfish, if using. Sprinkle with parsley, drizzle with oil, and serve.