Scoop the seeds out of the squash and put cut side up on a baking sheet. Drizzle with half the oil and season generously with salt and pepper. Turn over and roast until tender, about 40 minutes, when you can easily pierce through with a knife.
While the squash is roasting, heat the remaining oil in medium saucepan. Add the onion and pepper and cook until softened. Season with salt and pepper and add the garlic. Cook for a minute, add the quinoa and broth. Bring to a boil.
Reduce heat and cover. Cook for 15 minutes and turn the heat off. Let sit covered for 5 minutes.
Uncover, add the chopped kale and stir until wilted.
When squash is done, fill the cavity with the quinoa mixture and serve.