Toss the squash in olive oil and salt and pepper, roast at 425 for about 20 minutes. Heat about one tablespoon of olive oil in a large saucepan over medium-high heat. Add the leeks and sage and cook, stirring occasionally, until softened, about 5 minutes. Add the cooked squash and cooked quinoa to the pan. Then add baby spinach, a few handfuls at a time, gently stirring until it just begins to wilt. Remove from the heat. Sprinkle with the pine nuts. Season with salt and pepper, to taste.