Cut the butternut squash in half lengthwise. Scoop out and discard the seeds, then put both halves on a parchment lined baking tray, cut side up.
Drizzle the olive oil over the squash and rub around to coat. Bake for 60 to 75 minutes until the squash is cooked and fork tender.
Remove from the oven. When cool enough to handle, scoop out the flesh in the center of both squash halves, leaving about a one-inch border from the edge.
To prepare the stuffing:
Heat the oil in a large pan over medium-high heat.
Sauté the carrots, celery, onion, and garlic until soft and just browning. Add the wild rice and broth to the pan, stirring, and then cover and bring to a simmer. Cook for ten minutes.
Next add the white rice to the pan, cover, and continue to cook for eight to ten minutes until the rice has fully absorbed the broth and cooked through.
Stir in the pumpkin seeds, dried cranberries (or raisins), sage, thyme, salt, and pepper.
Add in the scooped out and chopped squash flesh. Stir well to combine.
Remove from heat and pile the stuffing into one half of the previously roasted butternut squash. Carefully top with the other piece and tie together with kitchen twine.
(Make ahead option: let it cool, cover with foil and store in the fridge for up to three days until ready to bake).
To bake: Bake at 350C for 20 to 35 minutes until hot all the way through. Slice and serve.