Preheat the oven to 200° C (390° F).
Cut the squash in half, scoop the seeds out and drizzle with 1 tablespoon of olive oil.
Place them on a baking dish and roast for 50-55 minutes, or until soft and slightly caramelised on the sides.
While the squash is roasting, start preparing the base of the soup.
Place a large heavy-based pan or Dutch oven on medium heat, and add 1 tablespoon of olive oil. Add the onions and sauté until translucent.
When the onions are soft, add turmeric powder, garam masala, chilli flakes, freshly ground black pepper, and salt. Sauté for another minute.
Stir in the tomato paste along with the garlic&ginger paste. Sauté for another minute, stirring continuously.
Add coconut milk and give it a good stir.
Stir in the stock, bring the mixture to a boil and let it gently simmer for 30 minutes, until the butternut squash is roasted and ready.
When the butternut squash is cooked, let it cool down until it can be handled and scoop the flesh out using a spoon.
Place the roasted squash and the soup base in a blender and blitz until smooth. Alternatively, you can use a hand blender or a liquidiser.
Return the soup to the pan if you want your soup piping hot or serve straight from the blender with a slice of crusty bread!