1. Preheat oven to 375 degrees. Boil water for pasta. Place an 18-by-30-inch piece of foil on a rimmed baking sheet. Place cockles and onions in the middle.

2. Squeeze seeds and juice from tomatoes (not cherry), and discard. Cut into 1-inch chunks; add to foil packet along with cherry tomatoes. Add olives, wine, oil, thyme, and oregano; season with salt and pepper. Toss to combine. Fold foil into a tight packet; seal ends well.

3. Bake until onions are tender and cockles have opened, 25 to 30 minutes. Discard any unopened cockles.

4. About 10 minutes before packet is done, add salt and pasta to boiling water. Cook until pasta is al dente according to package instructions. Drain pasta in a colander; transfer to a serving dish. Dot with butter; toss to coat pasta evenly.

5. Carefully open packet to allow the steam to escape; turn out contents onto pasta. Toss to combine. Sprinkle with parsley, and serve immediately.