Pre-heat oven to 350 degrees. Arrange squash, potatoes, and parsnips right-side up on a baking sheet.
Roast squash, sweet potatoes, and parsnips and squash for 30 minutes.
Flip the vegetables and cook an additional 20 minutes. The vegetable should be tender and cut very easily.
When finished cooking, scoop squash from skin and place in a soup pot. Place potatoes and parsnips in the pot as well.
Add chicken broth, water, salt, pepper, curry powder, and thyme.
Blend with an immersion blender, or place in a blender and pulse till smooth.
Add the cream and blend. Serve.
Optional topping: swirl a little sour cream or yogurt on top of the soup