Cut zucchini in half lengthwise. Scrape seeds and flesh from the inside of the zucchini, leaving about 1/4 inch flesh next to the skin. Place the pulp in a bowl. With a sharp knife, cut a thin slice from the bottom of each half so squash sits flat.
Brush the inside of the squash with butter. Place on a foil covered cookie sheet and cover with another sheet of foil.
Bake at 350 for 15 minutes or until squash is tender.
Cook quinoa according to directions. Set aside when done.
Meanwhile, in a large skillet, cook the sausage, breaking it up as you go. Remove from pan when cooked.
Saute celery, onion and mushroom in oil in the pan you used for the sausage, until tender. Stir in cranberries and cook until cranberries pop.
Remove from the heat.
Add the quinoa to the sausage mixture and mix well. Add the sage, thyme and salt and pepper. Add the zucchini pulp and stir well.
Stuff the squash and place back in the oven for 5 - 10 minutes.
Sprinkle with Parmesan cheese (if desired.