Heat the olive oil in a large pot over medium heat. Add the diced onion and sauté for about 5 minutes until translucent.
Add the minced garlic to the pot and cook for another 1-2 minutes until fragrant.
Stir in the cubed butternut squash and sauté for about 5 minutes.
Pour in the vegetable broth and bring the mixture to a boil. Add the ground cumin, nutmeg, salt, and pepper.
Reduce the heat to low and cover. Let it simmer for about 20 minutes, or until the squash is tender.
Remove the pot from heat. If using an immersion blender, puree the soup directly in the pot until smooth. Alternatively, transfer the soup in batches to a regular blender and blend until smooth.
If desired, stir in the coconut milk for added creaminess and adjust seasoning as needed.
Serve hot, garnished with fresh parsley.