Preheat oven to 325 degrees F.

Place squash halves, cut sides down, in a ceramic baking dish.

Add 1/8-inch water to baking dish. Cover baking dish with foil

Bake 35-40 minutes or until tender. Remove from oven and cool.

Add butter to stockpot. Melt over medium heat.

Sauté onion 5 minutes, or until soft. Stir frequently.

Scoop squash out of shells. Add squash flesh to onions.

Stir in stock and heavy cream.

Reduce heat to low.

Simmer 20 minutes.

Puree the soup in a blender or food processor.

Season with salt and pepper to taste and serve.