Preheat the oven to 180C. Place half the sage, all the pumpkin and garlic in a shallow baking dish. Heat half the olive oil and half the butter together until melted, pour over the pumpkin and toss to coat.
Bake for 15 minutes or until the pumpkin is tender. Remove from the oven, remove the pumpkin and sage (set aside) and return the garlic to the oven for another 15 minutes. Remove and set aside.
Meanwhile, heat the remaining oil and butter in a large, heavy-bottomed pan over medium heat. Add the onion and cook until soft. Add the rice and stir to coat well. Add the wine and stir until absorbed.
Start adding the hot stock, a ladleful or two at a time, and stir constantly until the liquid has been absorbed. Continue adding the stock and stir until the rice is plump and creamy but still has some bite. This should take 20-25 minutes. Season to taste and stir in the pumpkin/sage mixture and goat's cheese. Squeeze the roasted garlic out of its skin and stir through.
Remove from heat and sit for a couple of minutes before serving.
Serve sprinkled with remaining sage and drizzle with extra virgin olive oil (optional).