Preheat the oven to 450 degrees. Line a small baking sheet with parchment paper.
In a medium bowl, toss squash with clarified butter, cinnamon, nutmeg, and 1/4 teaspoon salt. Transfer squash to prepared baking sheet and roast for 15 minutes, or until golden and fork-tender. Remove from oven and set aside at least 5 minutes.
Meanwhile, in a small saucepan, heat 2 tablespoons butter over medium-high heat. Add onions, 1/4 teaspoon salt, and pepper and cook until onions are soft, about 2 minutes. Add pears and chicken broth and bring to a simmer. Cook for 5 minutes or until barely tender. Stir in remaining 1 tablespoon butter. Remove from heat. (You don't want to cook pears too long; you want them to retain their shape.)
In a medium mixing bowl, combine roasted squash, rosemary, and braised pears with their cooking liquid. Toss gently to combine. Serve warm.