Saute onions in oil in soup pot. Add lentils, water, ginger, turmeric and cumin. Cook gently until lentils are tender, 45 minutes or so. Add salt and pureed squash, and more water if needed. Heat thoroughly and serve. Makes 8-10 servings.
*The easiest way to cook squash is to split it into quarters, scrape out the seeds and place pieces cut-side-down in a baking dish. Add about a half-inch or less of water. Roast at 400 degrees for 45 min. to 1 hour, or until soft. Allow to cool, scoop out of skins and puree with food processor or blender.