Preheat the oven to 200°C and grease a large ovenproof dish.
Slice the butternut lengthwise and remove the seeds OR Slice the butternut in 1,5cm slices and remove the skin and seeds.
Place the butternut into the oven dish and drizzle with 1 tablespoon of olive oil. Season with salt and pepper and roast for 25 - 30 minutes.
While the butternut is roasting, heat the remaining oil in a large frying pan and sauté the onion and garlic over medium heat until translucent.
Add the celery and carrot and stir-fry for another 3 minutes.
Add the cooked brown rice, honey, soya sauce and nuts and stir-fry until everything is combined well. Be careful as the rice tends to stick to the pan.
Season with salt and pepper.
When the butternut is nearly tender, remove from the oven and top with the brown rice mixture. (See note)
Put the butternut back into the oven and roast for another 10 to 15 minutes.
Serve as a side dish to roast meat or as a main vegetarian dish with a salad.