Preheat the oven 375°F.

Place the spaghetti squash on a baking sheet. Pierce it on all sides with a knife. Bake in the oven for about an hour, or until easily pieced with a knife.

Allow to cool enough to touch. Then cut the squash in half and spoon out the seeds and pulp. Using a fork, scrape out the spaghetti squash, separating the strands as you go. It should yield about 2-4 cups.

Place the spaghetti squash in a bundle of dish towels (or a kitchen towel), and squeeze out some of the moisture (as Jor says, no one likes soggy spaghetti!!). Place in a mixing bowl, then toss together with the salt and tomato sauce. Add half of the ricotta and gently toss until the ricotta is just slightly broken up but not totally incorporated. Pour the squash into a small casserole dish or oven-safe bowl, dot with the remaining ricotta, and bake under the broiler until browned on top, about 5 minutes.

Serve immediately, or allow to cool, pack up, and take to your next potluck. Reheat in the oven on site.