Preheat the oven to 300º.
When the oven is up to heat, put the squash on its side on a baking sheet lined with foil or parchment paper, and bake it for 3 hours. When it's done, the skin should be caramelized and easy to pierce with a fork.
Let the squash cool for at least 15 minutes, then cut it in half lengthwise, scoop out and discard the seeds, and spoon out the flesh into a bowl.
Sprinkle the scallions with salt and sautée them in olive oil over medium-low heat until they're fragrant (about 1 minute).
Add the squash, sugar, and sesame oil, and mix well. Sprinkle with salt and pepper and cook for another 5 minutes.
Enjoy as a side or a low-carb base.