Preheat your oven to 400°F (200°C). Cut the sweet potatoes into wedges and arrange them on a baking sheet. Drizzle with olive oil and season generously with salt and pepper. Roast for 25-30 minutes until tender and caramelized, turning once halfway through.

In a large pot, heat a splash of olive oil over medium heat. Add the diced onion and sauté for about 5 minutes until softened and translucent. Stir in minced garlic, dried thyme, rosemary, and basil, cooking for another 1-2 minutes until fragrant.

Add the roasted sweet potatoes to the pot along with the vegetable broth. Stir to combine and bring to a boil, then reduce the heat and let it simmer for 10-15 minutes.

Using an immersion blender, blend the soup until smooth and creamy. Alternatively, transfer to a regular blender in batches.

Stir in the coconut milk or heavy cream, heat for an additional 5 minutes, and adjust seasoning with salt and pepper.

Ladle the soup into bowls, garnishing with reserved sweet potato wedges and fresh herbs. Serve warm.