In a kettle, cook the onion and garlic in margarine until soft, stirring occasionally. Add the cubed squash, apples, walnuts, cider, salt, pepper, allspice, cinnamon, cloves and enough stock to cover. Bring the mixture to a boil and simmer, partially covered, 1 hour or until squash is tender. If using canned, frozen or already cooked and pureed squash, add to other ingredients, bring to a boil and simmer for 10 minutes - start with a small amount of stock and add more if needed. Garnish and serve. In batches, puree the bisque in a blender or food processor until very smooth. Return to a clean pot and add brown sugar and, if needed, more salt and pepper. If desired, add cheese and stir until smooth. To thin to desired consistency, where ripples disappear, add cream or more cider. To serve, reheat until piping hot, but do not boil. Serve garnished with dollops of whipped cream and/or a dash of allspice and more chopped walnuts. NOTE: To precook squash without peeling, cut in half, remove pulp and bake, cut side down, in a baking dish with enough water to cover the bottom until tender, about 45 minutes at 375 degrees. Check occasionally to see if more water is needed. Then scrap pulp off the skin.