Preheat your oven to 400°F (200°C). Spread the cubed butternut squash on a baking sheet, drizzle with olive oil, and toss to coat evenly.
Roast the squash in the oven for about 25-30 minutes, until the edges are golden and caramelized, and the pieces are tender when pierced with a fork.
While the squash roasts, heat a large pot over medium heat. Add the chopped onion and cook until it becomes translucent and fragrant, about 5 minutes.
Add the minced ginger to the onions and cook for another minute, allowing the aroma to intensify.
Once the squash is finished roasting and cooled slightly, add it to the pot with the sautéed onions and ginger. Pour in the vegetable broth and bring to a gentle simmer.
Use an immersion blender or transfer the mixture carefully to a blender. Puree until smooth and velvety, then return to the pot if using a blender.
Season the soup with salt and pepper to taste, then stir well. Allow it to simmer for an additional 5 minutes for flavors to meld.
Pour the hot soup into bowls, and serve with a drizzle of olive oil or fresh herbs if desired for added flavor and presentation.
