In a large pot, heat some olive oil over medium heat.
Add the chopped onion, carrots, and minced garlic to the pot. Cook until the vegetables are soft and fragrant, about 5 minutes.
Add the cubed butternut squash, vegetable broth, salt, black pepper, dried thyme, and nutmeg to the pot. Bring to a boil, then reduce heat and let simmer for about 20-25 minutes, or until the butternut squash is tender.
Using an immersion blender or regular blender, puree the soup until smooth and creamy.
Stir in the heavy cream and heat the soup for an additional 5 minutes.
Serve hot and enjoy!