Preheat the oven to 200℃ (400℉)
Slice the squash lengthways down the middle and place each side on a lined baking tray. Add around the squash other roast vegetables (baby potatoes, kumara (sweet potatoes), carrot, cashews, cranberries).
Place in oven and cook for 45 minutes to soften slightly
Meanwhile, we start on the stuffing. Blend the rolled oats in a food processor for around 30 seconds on pulse to create coarse flour.
Next add in the lentils, walnuts and apricots, and pulse until all is coarsely chopped but not a paste. Set aside.
In a frying pan, dry-fry with a small amount of water the onions until they are translucent. Then add in the mushrooms and garlic, and saute for 6-8 minutes.
Add in the herbs and gently mix through. Then add all the other ingredients, including the rolled oats mix, but excluding the squash. Mix and heat through, and set aside.
Once the squash is roasted, scoop out the seeds and discard.
Next using a spoon scoop out a channel down both pieces of squash at the same depth and the seed casing area.
Add the stuffing mix inside the scooped out sides, pressing in firmly and joining both squashes together. Tie it securely with some string to hold it together while it cooks.
Place the squash back in the oven still with the other vegetables for 15 minutes or until all vegetables are soft when pierced with a fork.