Preheat oven to 400 degrees F.
Slice the squash in half long ways and scoop out the seeds. Place the squash cut side down on a baking sheet.
Add a cup of water to the pan to keep the squash from sticking and to help roast.
Bake for 30-45 minutes or until the thick part of the squash can easily be pierced with a fork.
Once cool, scoop out the pulp and discard the skin.
In a large soup pot over medium-low heat, melt the butter. Add the chopped onions and ginger. Cook for 5 – 8 minutes until tender.
Add the squash pulp to the pot along with chicken stock.
Bring to a simmer for 10 minutes, stirring often.
Puree the soup either with a hand immersion blender or in a counter top blender. Be careful because it is hot and can splatter out.
After the soup has been pureed, stir in the cream and salt.
Ladle into soup bowls and serve warm with crusty bread.