Heat oil in a large saucepan over medium heat. Add fennel, onion, and garlic and sauté until onions are golden. Add pumpkin, chilli/cayenne, and quinoa with half the pistachios and sauté for 4 to 5 minutes. Stir in 720ml (twice the volume of the quinoa) of hot water with the salt, pepper, and nutmeg. Cook, stirring occasionally until the quinoa is tender, the pumpkin is cooked, and all the moisture is absorbed.