Loosely based on the Moosewood's "Comprehensively Stuffed Squash"
Would make a great thanksgiving dish for vegetarians, fairly simple for a weeknight meal as well. You can improvise with what you have on hand.
Cut squash in half, remove seeds, and bake, cut side down, at 350 degrees for 30 minutes.
Meanwhile, saute onions, celery, and carrot in butter or oil until soft and translucent. Add garlic and mushrooms, and continue cooking until they are soft and have released their juices. Add sherry to "deglaze" the pan, and allow to simmer briefly.
Add bread cubes, raisins, sunflower seeds, sun-dried tomatoes, and walnuts, stir to combine. Add sage and salt/pepper to taste, then enough broth to soften; remove from heat.
Once cooled slightly, stir in shredded cheese.
Add stuffing to interior of squash, mounding as needed, and bake covered another 20-30 minutes. For a crunchier top, remove cover for the last 10 minutes.