Preheat the oven to 375ºF. Season the squash with salt and pepper. Place cut side down in a 9-by-13-inch baking dish. Add 3/4 cup water, and roast until tender when pierced with a knife, about 45 minutes. Let cool.
2
When about 25 minutes have passed, on a rimmed baking sheet, toss the shrimp with 1 teaspoon oil and season with salt and pepper. Roast until cooked through, 8 to 10 minutes.
3
Scoop out the seeds from the squash and discard. With a fork, scrape the flesh into a large bowl. Add the shrimp and any cooking juices, lemon juice, and 1 tablespoon oil; toss to combine. Season with salt and pepper, top with parsley, and serve with lemon wedges.