1. Roast the Squash
   Preheat the oven to 400°F (200°C). Drizzle the butternut squash halves with olive oil and place them cut side down on a baking sheet. Roast for 30-40 minutes, or until tender. Remove from the oven, let cool slightly, and scoop out the flesh.
2. Sauté the Aromatics
   In a large pot, heat a tablespoon of olive oil over medium heat. Add the diced onion and sauté until translucent, about 5 minutes. Add the garlic, curry powder, cumin, turmeric, and ginger. Cook for 1-2 minutes, stirring frequently, until fragrant.
3. Add Squash and Broth
   Add the roasted squash flesh to the pot, stirring to combine with the spices. Pour in the vegetable broth and bring the mixture to a boil. Reduce the heat to low and let it simmer for 15-20 minutes.
4. Blend the Soup
   Use an immersion blender to purée the soup until smooth. Alternatively, carefully transfer the soup in batches to a blender and blend until smooth.
5. Season and Serve
   Season with salt and pepper to taste. Serve hot, garnished with fresh herbs or a swirl of coconut milk if desired.

Enjoy your cozy and flavorful soup!