Preheat the oven to 200° C.
Place the butternut squash in a roasting dish and toss with 1tbsp of the olive oil. Bake for 20 minutes or until tender. Reserve at room temperature.
Heat the remaining oil in a large saucepan. add the onion and garlic and cook for 5 minutes. Add the rice and stir to coat with the oil.
Add 1 cup of warm stock to the rice at a time. Stir constantly until the stock has been absorbed. Continue until the rice is tender. Stir in the spinach, roasted squash and parmesan. Season to taste with salt and pepper. Serve with extra grated parmesan.