- Saute onion in broth or water in large saucepan over medium heat until onion is translucent, about 6 minutes
- Add potatoes, squash and broth.
- Simmer, covered, until veggies are tender, about 25 minutes.
- Cool slightly.
- Working in batches, place the veggies with their liquid in food processor whirl until puréed.
- Return the purée to the saucepan.
- Stir in the non-fat milk for desired consistency.
- Season with salt and pepper.
- Heat over low heat.
- Top each serving with dollop of nonfat sour cream and a sprinkle of nutmeg.