Cut pumpkin into 12 wedges. Remove seeds but leave skin on. Place pumpkin and onion in a large roasting pan, sprinkle with cinnamon, drizzle with oil and toss well.
Bake in a 200C oven (fan-forced) for 40-45 minutes, turning pumpkin and onion halfway, until tender.
Meanwhile, to make glaze, combine maple syrup, mustard, thyme and soy sauce in a small bowl.
Drizzle glaze over pumpkin and onions. Return to oven. Bake for further 8-10 minutes or until pumpkin and onion are browned and glaze is sticky.
Sprinkle with extra thyme to serve.