1. Heat olive oil or butter in a large pot over medium heat.

2. Add chopped onion and cook until soft and lightly golden, about 5 minutes.

3. Stir in minced garlic and cook for 1 minute.

4. Add frozen butternut squash cubes and pour in broth, then bring to a gentle boil.

5. Reduce heat and simmer for 15 to 20 minutes until squash is tender.

6. Use an immersion blender to puree the soup until smooth, or blend in batches in a countertop blender.

7. Return soup to the pot if needed and stir in heavy cream or coconut milk.

8. Season with salt, pepper, cinnamon, and nutmeg as desired.

9. Ladle into bowls and garnish with toasted pumpkin seeds or croutons before serving.