Place pumpkin in a baking tray with 3cm of water and cover with foil. Bake pumpkin in the preheated oven for 1 hour, or until flesh is fork-tender. Keep warm.
In a saucepan, bring water to a boil. Add rice and stir. Reduce heat, cover and simmer for 20 minutes.
Meanwhile, place Brussels sprouts, carrots and chickpeas in a frypan over medium high heat. Stir together soy milk, soy sauce, turmeric and garlic, and add to the frypan, tossing to coat. Cover and simmer for 20 minutes, or until tender. Add a small amount of water or more soy milk-soy sauce mixture, as needed, to prevent drying out.
Combine rice with vegetable mixture and scoop into pumpkin. Serve with additional soy sauce and season to taste.