Rice noodles turn this warm salad into a main course.
Preheat the oven to 400 degrees. Fold four 18-inch lengths of parchment paper in half, cut into a half-heart shape, and open. In a medium bowl, combine the onion, cucumber, tomatoes, cilantro, chile, squid, and shrimp. Divide the seafood mixture among one half of each parchment heart near the crease. Fold the other half of parchment over ingredients. Make small overlapping folds to seal edges, starting at the top of the heart. Two inches from the end, twist the parchment twice, gently but firmly, to seal.
Place the packet on a rimmed baking sheet or in a heavy skillet (preferably cast iron), and bake 15 minutes or until fully puffed. Remove from the oven, and let sit while preparing the dressing. Whisk together the sesame oil, rice-wine vinegar, salt, and pepper in a small bowl. Open the packet carefully, and transfer the mixture to a serving plate, discarding the cooking juice. Drizzle with the dressing, and serve hot or at room temperature.