Cut squash in half, take the seeds out and place, cut side up, in a baking dish. Season with salt, pepper, and 1 tablespoon olive oil. Add 1/4 inch of water to baking dish.
Cover baking dish with foil & bake for around 40 minutes, or until tender when pierced with a fork.
Reduce oven temperature to 375 degrees F.
In a small pot, bring 2 cups water to boil and add quinoa. Reduce to a simmer and let cook for 15-20 minutes, or until quinoa has absorbed all water. Remove from heat.
In a pan, heat remaining olive oil and saute mushrooms and onions on medium heat. Add in the garlic after a few minutes. Cook until fragrant and onions are translucent.
After squash has cooled, scoop out the insides, leaving flesh about a 1/4 inch thick.
In a large bowl combine quinoa, butternut squash, mushrooms, onions and garlic, and parmesan cheese. Mix well and season with salt and pepper.
Spoon mixture back into the hollow butternut squash (add additional grated cheese, Gruyer is great on top) and return them back to the oven for 20-25 minutes, or until top is golden brown.
