Preheat the oven to 400°F (200°C). Spread the cubed butternut squash on a baking sheet, toss with 1 tablespoon of olive oil, and roast for about 25-30 minutes until tender and slightly caramelized.
While the squash roasts, chop the onion and grate the fresh ginger. Set aside.
In a large pot, heat a splash of olive oil over medium heat. Sauté the chopped onion until translucent and fragrant, about 5 minutes.
Add the grated ginger to the onions and cook for another minute until aromatic.
Pour in the vegetable broth and bring to a gentle simmer. Add the roasted butternut squash to the pot and cook for 5 minutes to meld flavors.
Use an immersion blender directly in the pot, or transfer the soup in batches to a blender, and blend until smooth and velvety.
Return the blended soup to the pot (if using a blender). Stir in the coconut milk and season with salt and pepper to taste. Heat gently until warmed through.
Taste and adjust seasoning with more salt and pepper if needed. The soup should be rich, smooth, and flavorful with a hint of ginger heat.
